It seems to work on some projects but not all (all are standard C++ win32 projects). Regardless of whether it's working or not, the Tools|Options|ViEmu settings dialog does exist, and the enable viemu tickbox is alway ticked. Pressing Ctrl-Shift-Alt-V makes no difference.
Below is the paste from Help|About. Note that I've not changed any addons since it stopped working.
Microsoft Visual Studio 2005
Version 8.0.50727.762 (SP.050727-7600)
Microsoft .NET Framework
Version 2.0.50727 SP1
Installed Edition: Professional
Microsoft Visual C# 2005
Microsoft Visual C# 2005
Microsoft Visual C++ 2005
Microsoft Visual C++ 2005
Microsoft Visual Web Developer 2005
Microsoft Visual Web Developer 2005
Microsoft Web Application Projects 2005
Microsoft Web Application Projects 2005
Version 8.0.50727.762
Microsoft Visual Studio 2005 Professional Edition - ENU Service Pack 1 (KB926601)
This service pack is for Microsoft Visual Studio 2005 Professional Edition - ENU.
If you later install a more recent service pack, this service pack will be uninstalled automatically.
For more information, visit http://support.microsoft.com/kb/926601
NGEDIT Software's ViEmu v2.2.6
ViEmu 2.2 - vi/vim editor emulation for Microsoft(TM) Visual Studio(TM)
(c) 2005-2008 NGEDIT Software (www.ngedit.com)
Visual Assist X
For more information about Visual Assist X, see the Whole Tomato Software website at http://www.WholeTomato.com. Copyright (c) 1997-2008 Whole Tomato Software, Inc.
Xbox 360 Extensions for Visual Studio 2.0.6534.0
The Xbox 360 Extensions for Visual Studio add the ability to develop, build, debug and deploy game projects for Microsoft Xbox 360. Version 2.0.6534.0
Xoreax IncrediBuild 3.30 (build 892)
Xoreax IncrediBuild 3.30 (build 892)
ProDG VSI
ProDG Visual Studio Integration
Version 1.7.11
Copyright © 2003-2008 Sony Computer Entertainment Inc. / SN Systems Limited
See http://www.snsys.com