I wonder if They can work perfectly together...
The simple answer is yes - I have both installed on the machine I'm replying to this question from. :=)
I have both running on my machine and all seems to be fine after 2 weeks of use...
Yes VS'08 and VS'05 will work nicely when installed on the same machine.
Now, if only they made the .NET 2.0 support in VS'08 use the same solution/project file version number as VS'05 so you could easily move back and forth VS versions with the same project without modification.
Yes, they work well together. Refer to Installing Visual Studio Versions Side-by-Side on MSDN for more information.
You may need to install VS2005 before VS2008 though, or you're file associations may end up not working correctly.
I have VS2005 installed. But I was afraid about installing VS2008 and lose everything.
I think I have to install 3.5 framework first. Is that correct?