CRM5 is currently on the way and most likely to be shipped sometime in early 2010.
(CodeName :  Microsoft Dynamics CRM “V.Next”)
So what can we expect...... read below for the answers

New Features for Users
========================

Enhanced Navigation
CRM5 uses the same "Fluent UI" (aka the Ribbon) as Office 2007. This new "command bar"
replaces the CRM 4.0 "tool bars" at the top of each page, and is
context sensitive. In addition, the "command bar" is fully
customizable and you can add your own buttons much like you can with ISV.Config
file today.

No more Tabs
The form model in CRM 4.0 made use of tabs to divide a form into multiple
pages.
In CRM5 tabs are displayed in the same way as section, with each form just
having a single, scrolling page.

Grid Filtering
Apart from sorting, CRM5 now allows filtering on any available column in
the Grid, much like Excel
Possibly there would be an option to save the filtered view as well.

In-line Visualizations
CRM5 allows you to visualize numeric data using in-line charts
within the form itself. This is not SQL Server Reporting Services, but looks
very much like the .NET charting solution from Dundas.
One can select a number of different chart formats such as Bar, Column, Funnel,
Line, Pie & Scatter.

Team Ownership
CRM5 now also supports Team Ownership apart from the already existing ones (User owned and Organization owned). A good needed
feature indeed.

Sharepoint Integration
Integration with Windows Sharepoint Service now comes Out of the Box
This includes document management, which includes site and document library
provisioning, document metadata, item security, and check-in/check-out
capabilities.

Queue
CRM5 now seems to support the "Add to Queue"
command, from which we believe the one should be able to add any entity
(including custom entities) to a Queue.

New Features for Administrators
=============================

Form  Layout
More flexibility has been added to Form Design, wherein Administrators can
now position sections side-by-side, field label can be positioned on the
top,left , right for any control
But the one below takes the icing on the cake.
Inline Child Grids are now supported OOB for related child entities. You now
don’t need custom coding to make this work.

Filtered Lookup
Finally one of the most desired feature since the 1.2 release, has made its
presence available in CRM5.
A lookup can now be customized to display data from any pre-defined view or
filter by related lookup on the same form.

Form Headers & Footers
Since all fields,sections,tabs now come on a single page,  a form could become quite long, and scrolling
to find the required fields  could be a
headache. CRM5 now supports placing the commonly required fields on the header or footer,
so that they will always be displayed regardless of the
scrolling.

Solution Management
With CRM 4.0, you had to implement a manual process when customizing your
solution, to make sure that you didn't overwrite previous customizations, or
disrupt any 3rd party ISV solutions. In CRM5 we had now added the concept of
solutions.

      A solution is a defined set of entity customizations, workflows, e-mail
      templates, security roles, plug-ins etc. that can be managed as a single
      unit. Each solution is version controlled so presumably your can have
      multiple versions of the same solution installed, and roll-back to a
      previous version if necessary.

      You can also define solution dependencies where one solution can only be
      installed if another solution is also installed. For example, you might
      have a base solution for your whole organisation, with a departmental
      specific solution built on top of it.

      Namespace collision is avoided by defining publishers, with each publisher
      having a unique namespace. This avoids the common issue where the default
      namespace "new_" is used for all customizations, leading to
      potential namespace conflicts.

      One final plus point is that you can now specify which attributes will be
      exported as part of a solution, rather than having no choice but to export
      the whole entity.

Global Picklists
With CRM5, you now have the option of defining a Global Picklist,
which can be used across multiple forms.

Drag & Drop Form Editor
One of the most time consuming customization tasks in CRM 4.0 is the form
design. Every time you want to add, remove or re-position tabs, sections and
attributes, you have to go through a multi-click process. With CRM5, you can
now drag and drop all elements of a form, speeding up the process considerably.

Audit
Audit functionality on attribute level, it seems now comes OOB.
An Auditing  field now appears within the
Attribute setting, which can be set to True or False.

New Features for Developers
==========================

Custom Code Sandbox
There is a new server role for running custom plug-in code and custom
workflow activities without requiring full trust. This means that it will be
possible to run custom code in the CRM Online environment and achieve true
parity between On-Premise, Partner-Hosted and Microsoft-Hosted deployments.

Plug-In Transaction Support
In CRM 4.0 you could register a plug-in to run either before (pre-event) or after (post-event) the CRM platform
operation. However, you were not able to run as part of the transaction itself,
so you had to right your own compensation logic in the event the CRM platform
operation failed. CRM5 addresses this limitation and you can now choose to
register you plug-in as part of the platform operation. The CRM5 plug-in
registration tool has been modified to support this.

Automatic Plug-In Profiling
CRM5 will keep track of how a plug-in is
executing, what resources it consumes, if it is causing unexpected exceptions
and whether or not it is violating security constraints. If a particular
plug-in fails a number of times it is automatically disabled from executing,
helping to maintain system integrity.

Courtesy :  http://blogs.msdn.com/ukcrm/archive/2008/11/10/what-s-new-in-crm5.aspx