Atmel Studio 6.1 review
Up front, so there is no ill feelings – this review is my attempt to provide objective information, no criticism is intended. It is in no particular order and all the info is provided in good faith.
1. The latest January 2014 beta of Visual Micro is a bust. The crasher is back. A single keyboard entry to edit tab will crash the XP (SP3)
2. The initial installation, about a month ago worked just fine, i9ncluding VA,  but would occasionally crash the XP when editing..
3. After several uninstall of both Studio and VisualMicro the crasher disappeared, but VisualAssist quit working in .ino file. Many reloads / registry (recommended by this forum) write did not fix the VA. Getting somthin gto the effect – symbol could not be found. BTW worked fine in VAView.
4. Downloaded cpp file and VA worked as expected in editor, but sill no work on ino file.
5. Dow loaded January 2014 beta. Of VisualMicro. It would not install when thedownolad was saved on my PC, error in CAB file. But it installed via run from web, albeit with no progress  / done indication.
6. Reinstalled Studio.
7. Previously saved Solution has working VA , as expected – but I get strange VA report. Here is a copy.

Intellisense build error: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at Visual.Micro.Visual.Studio.Arduino.AddInApp.RefreshIntellisenseOfSketch(Project oProject, SketchBuilder sk)


8. Entering single keyboard character into solution crashes the XP – again! 
9. There a  new pull down combo box with “ Visual Micro?” (sic) entry in it. It does contain something about manager “<...>” (sic) but I get no reaction when selected. 
10. The Arduino board pull down is empty.
11. I am unable to open anything ( New / Open) Arduino – the “Sketch IDE” is grayed out.

I'll happy to provide additional info to  my best abilities, however, commentaries like “it woks fine here, you have a virus , upgrade to quad CPU and Window 10 plus”  will be cheerfully ignored. 

I personally feel the only solution is a start over with clean install of Atmel Studio, and I mean clean up the directories and registry. Repairing both Studio and VisualMicro just does not do it.
Cheers Vaclav 

OK, I got the IDE to play with VA. I had two versions of VisualMicro installed. So the installer is not that smart.
BUT IT STILL CRASHES, big time! On single keystroke in editor.
I need to take a break and do some productive coding - back to Arduino IDE. YUCK!