As of this morning, the RTM version of Visual Studio 2008 (was codenamed Orcas) is available for download from the MSDN subscribers site.
Now I'm going to sound like a licensing guy for a second, but stay with me because I might have good news for you. If you have an MSDN subscription, you have software assurance for Visual Studio. This means that your MSDN subscription Licences you to use all the versions of Visual Studio that are released during the term of your contract. i.e. if you have an MSDN subscription, you have already paid for your rights to use 2008 - go get it, go use it :-)
For my money, the killer feature is the new build triggers and build retention features. This allows you to do continuous integration out of the box and should help ensure that you don't ever run out of disk space on your build server. For more details on this feature, have a watch of the Channel 9 video:
Also included is .Net Framework 3.5, new language features (including LINQ), designers for WPF, WF - but I'm a TFS guy and an naturally biased as to what the best bits are :-). For some other opinions: