Woo hoo! STL/CLR is back! It made an accidental brief appearance in a Whidbey beta, but wasn't ready for prime time at all and went off for some retooling. If you grab the September CTP of Orcas, you can give it a whirl yourself. Here are some links stolen from Nikola's blog announcing it:
http://www.microsoft.com/downloads/details.aspx?FamilyID=82243606-d16d-445c-8949-9ee8c10cda2e%26DisplayLang=en to download the CTP.
http://connect.microsoft.com/VisualStudio/ to report bugs or issues with the CTP including STL/CLR.
http://blogs.msdn.com/vcblog/archive/2006/09/30/777835.aspx Known issues and some workarounds.
So many paying projects to finish... but I will get working with this soon. Time to adjust my November talks to stop using the old unofficial version and start using the CTP version.