It was released as a Beta for Lion linked - from a page about Mountain Lion, on the Apple Web site.
It will be released as a full version in Mountain Lion.
What will stay and what will go cannot be speculated about (Apple does not allow this on the Boards)
Anyone using a developer version of Mountain Lion cannot say either.
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
iMac 2.5Ghz 5i 2011 (Lion 10.7.2)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.6.8),
"Limit the Logs to the Bits above Binary Images." No, Seriously