There is a bug where even if you have applied a patch or service pack to SSIS 2008, the version listed next to the “Integration Services” service in Management Studio continues to show 10.0.1600, which is the version number for RTM.
As always, if you are unsure, it is best to determine the actual version by looking at the files themselves, ie. dtexec.exe, or by confirming the version number in BIDS via Help->About.
While this isn’t a big deal, it is an annoyance. I’ve got the question out to the product team for their response, so stay tuned for more information as it becomes available.
EDIT – Please see Matt Masson‘s (SSIS Product Team) comments below.