I have VS2010 and Arduino 1.0 IDE, and got the current VisualStudio addin yesterday.
Toolbar and Menu items show up, 
I solved the issue with the wrong target boards, chose "Uno" as my target.

Trying to compile a dummy .ino with 
[tt]void setup() {}
void loop() {} [/tt]
fails with 10 errors, starting with  
[color=#ff0000]IntelliSense: expected a '{'      
c:\program files (x86)\arduino-1.0\hardware\tools\avr\avr\include\stdlib.h      106      13[/color]      

stdlib.h line 106 is 
extern void abort(void) __ATTR_NORETURN__;

and _ATTR_NORETURN__ is undefined because its definition ( in line 92 ) is skipped in a 
[tt]#ifndef __DOXYGEN__ [/tt]

__DOXYGEN__ however is defined in .Test1.vsarduino.h

Seems something unexpected with my VisualStudio, right ? 
How can I further drill this issue down ? 
or is this a standard issue, which I simply overlooked ?

Tim@Visual Micro wrote on May 14^th, 2013 at 9:22am:

1) Yes. That's what I hoped the VS environment is good for !
2) It compiles fine, or detects real errors if I provoke some.

Compiling 'Test2' for 'Arduino Uno'
Binary sketch size: 2492 bytes (8% of a 32256 byte maximum) (0.31 secs)
Upload requires a serial port or programmer. Upload cancelled.
or 
Uploading to I/O board using 'COM1'
avrdude: stk500_getsync(): not in sync: resp=0x00

...which is fine for me right now, without an arduino attached.

Thanks a lot for your fast and helpful response. 
I hope my next question will be harder