Following on from the release of the Cumulative Hot Fix 1 in February, Adobe have published a page within the Technote section of their site to list all hotfixes for ColdFusion 9:
http://kb2.adobe.com/cps/529/cpsid_52967.html
Sadly, as RSS feed for the releases does not yet exist, which would be uber-helfpul, but make sure you bookmark the link to ensure you stay up to date on hot fix releases for ColdFusion 9.
** edit **
@bigmadkev posted a link to an Adobe RSS feed that contains hot fix information, which you can find here: