Having installed Visual Studio 2010 beta 2 on my freshly-reinstalled netbook (now with Windows 7 and and SSD – yummy) I found that my solution file from Visual Studio 2010 beta 1 wasn’t recognised properly: double-clicking on the file didn’t do anything. Opening the solution file manually was absolutely fine, but slightly less convenient than being able to double-click.
After a bit of investigation, I’ve found the solution. Manually edit the solution file, and change the first few lines from this:
Microsoft Visual Studio Solution File, Format Version 11.00 # Visual Studio 10
Microsoft Visual Studio Solution File, Format Version 11.00 # Visual Studio 2010
It’s just a case of changing "10" to "2010".
Hopefully between this and the linked SuperUser post, this should avoid others feeling the same level of bafflement :)