AMD hasn't announced the 'RV740' desktop graphics chip and M97 mobile GPU but it has revealed their existence in its driver release notes.
The Catalyst chip ID table lists a stack of GPUs that the AMD driver package supports. Among them are a small number of generic "ATI Radeon Graphics Processor" parts, along with their relevant code numbers.
In addition to the RV740 and M97, there's also the M93. Also listed in the generic section are the RV710 and RV730, though these have been available as shipping product since Autumn 2008, as the Radeon HD 4450 and 4470 (RV710) and 4650 and 4670 (RV730).
RV740 is expected to be fabbed at 40nm and is destined for mid-range graphics cards with GDDR 5 memory. Two RV740s are listed.
There are two M97s, too, but only one M93. M97 is said by some to run at 500MHz and connect to GDDR 3 memory running at 850MHz. M93 runs at 550MHz, but its GDDR 3 is only clocked to 750MHz, it's claimed.
Both mobile chips are fabbed at 40nm. ®