Normally the inq isn't at all bad for this info, the info is leaked out because AMD/Nvidia and the partners won't people to know whats coming frankly.
The only thing is, it seems weird to me they'd release upclocked versions, then a dieshrunk version all within about 2 months of each other. thats a hell of a lot of core tweaking and changing for an incredibly short and expensive run with most likely smaller yields as most new processes get.
Its also very unlikely the new chips would have more shaders/TMU's unless they are dieshrunk. The whole point of redundancy in the chip(read the anand story on the RV770) is they went small and had basically no redundancy.
It takes a lot of time and effort to make new core revisions and costs a lot to tape out. Its always possible and ATi/AMD are at that point where they can afford to throw money around simply to peeve off nvidia and keep very competitive all the time. Logic would suggest they'll only do a 40nm refresh and it would sound like it should have higher clocks and probably a boost to shaders. the 5800 they were talking about said 1000 shaders per core(well they said 5800x2 with 2000 shaders total, 1000 each core) as opposed to 800 now its not a huge increase. the suggested extra TMU's would also suggest a pretty large change of Shaders per TMU which is a fairly big die change, while , shockingly 20% more TMU's (40 to 48) aswell as, lets see 25% more shaders, is a much more "inline" change and makes a lot more sense.
Otherwise we're look at , 4970/50 thats simply slightly faster, then a die shrink but not large architechture change, 2 months later, the 5870/50's, and then 5-6 months after that a DX11 part, so a 6870/50. ALl in one year, which would, with an entire range of cards mean new mid/low end parts at 40nm DX10.1 (5xxx series) and then all new mid/low end DX11 parts end of year. Seems incredibly unlikely to me for them to sell 4 different entire series of cards in 2009.