Will their be a new release of the compact framework with VS2010 and .net 4.0 and if so what new features will it include? WPF? linq to SQL? etc
I'm not sure about 4.0 for compact devices (although it seems likely), and I don't know about WPF either, but I can tell you they are going to provide Silverlight for mobile devices giving you access to a subset of WPF.
Haven't found any other references yet...
Visual Studio 2010 only supports developing for windows phone 7. This is a silver light based framework, it does not support win forms or native code.
VS2010 can not be used to develop for Windows Mobile 6.5 or lower.
You can however install VS2008 along side VS2010.
There's an unofficial release of CF 3.7 kicking around the intertubes:
It appears that someone ripped it off a ROM image and dropped it in a torrent.
From what I heard from guys in redmond, there will be a mobile silverlight platform for both windows mobile and nokia (symbian, I think). The "silverlight mobile" platform should be built on top of the compact framework, so it will NOT be a port of the desktop version.
There seems to be an information embargo on Windows Mobile right now, but I think things will be much clearer once Windows Mobile 7 is out.