I've been wondering why Sapphire was and is still the only manufacturer of 4850x2's. The only reason I can find is that it seems pointless when you can make a 4870x2. I guess other manufacturers see the 4850 as a lesser 4870, so why double it up? For the same reasoning, why double up a GTX275?
However, it is AMD's strategy to create high-end parts by doubling up mid-range parts, as we all well know. So I guess Sapphire took initiative. Am I correct in believing that the 4850 was a better seller than the 4870 because it became the bang-for-the-buck king? If so, Sapphire made a good move; it's unfortunate now that 4850 prices have dropped so far that the 4850x2 (both vram flavours) are at least £20-£70 more expensive than buying two separately. £20 might be feasible for multiGPU stability, single-slot pcix16 and security, but not £70. I think buyers are more likely to buy two separately and crossfire them themselves in the latter case. (Or, for slightly cheaper, a 4890 - the better choice of course.)
The 4770 is now the bang-for-the-buck king in the low-middle range, right? Doubling up seems like a smart thing to do (as many have crossfired already) and I think would be pre-judged on the success of the 4850x2 up until now. I wonder if the 4890 might also be doubled up. With all this activity on the 4xxx series, it seems to me that AMD are setting up an AMAZING set of previous-generation cards for when 5xxx hits.
Being someone who doesn't keep up-to-date, I'm looking forward to potentially cheaper 4xxx hardware. ^_^