I can't answer your question from personal experience (yet). However...
Apple' tech specs for the latest MBP has this:
Pure digital video output
- DVI output using Mini DisplayPort to
DVI Adapter (optional)
- VGA output using Mini DisplayPort to VGA Adapter (optional)
- Dual-link DVI output using Mini DisplayPort to Dual-Link DVI Adapter supports 30-inch Apple Cinema HD Display(optional)
- HDMI output using a third-party Mini DisplayPort to HDMI Adapter
The 2nd line of the video specs above appears to say yes... your VGA projector should work. I wish I had read this last week, because I was forced to migrate my PowerPoint seminar presentation to a (gasp!) Windows machine when the projector in use only supported VGA.
Bummer! A $20 dongle would have solved my problem.
The current MBP and the mid-2009 MBP both supported HDCP (High definition content protection)... which caused me to have to buy a new flat-screen monitor because my previous one didn't support HDCP. So... it appears that not all digital video is created equal. Even if your projector had DVI it might not work (unless it supports HDCP).
The following may shed some light on your topic