- the 8.95 release (Cat 12.3) includes support for HD 7870 but not HD 7850
- an 8.951 release which includes HD 7850 support (and HD 7750/7770) just exited QA in the last day or two
- the Catalyst folks are going to post the 8.951 Linux driver but I haven't heard back yet re: when it will go up
There are a lot more than 4 people working on it -- the in-house open source driver team is 4 AMD developers plus a number of community developers, but we're talking about the proprietary drivers which come from separate teams inside AMD.
I pinged the Catalyst folks again today re: posting schedule for the 8.951 driver.
ETA for web posting is Wednesday (Mar 28). I expect it will be another off-cycle release so don't know if it will have a Catalyst version number, but 8.951 is the internal version you're looking for. There will probably be an associated Knowledge Base (KB) record.