Not everyone knows as much about hardware as the users of this forum. They wouldn't have done this unless there was a market for it. Lots of people looking for an upgrade won't know about Bulldozer, will just see a fast quad core that fits their MB, or will buy a fast looking cheapish full system.
Its got nothing to do with knowing what might sell in the next month or three, this new chip will be around for ages to come, as will P2's. Over time yields increase, little tweaks to the process, power comes down slightly, they will sell tonnes of chips before Bulldozer launches and millions after, Dell boxes will have Phenom 2's in for the next year, minimum, maybe 2. Whats better, a £125 3.4Ghz 125W quad core, or a £125 3.6Ghz 125W quad core.
They don't "make" new chips, its not a new design, gradually over time they'll find the first batches can do 3.2Ghz at 125W all of them, and some will do a little lower, so they can sell the top bin at 3.2Ghz @ 125W, they'll test a sample of every batch every couple weeks, and 3 months later, those same chips are all now doing 3.2Ghz at 110W, and they can push to 3.4Ghz at 125W, so they just reclassify the models and the top one goes up slightly. This repeats itself with every chip ever made basically.
Phenom 2 will still outmuscle Llano in CPU terms, and not every Dell gets sold with IGP's so a Llano in a few months won't always be a better choice than a Phenom 2 in midrange gaming rigs and the like.
AMD don't go, Bulldozer then, nothing else gets made ever.
Firstly they are on 32nm the new stuff, which will be maybe, if lucky 10% of their overall capacity to start with. So right now 10% of the output of wafers, but only 2-3% of the capacity for chips (because lower end stuff is MUCH smaller so far more chips per wafer) will be Bulldozer/Llano, by the end of the year that will probably be up to 20-30%, by the end of next year they should be fully at 32nm. Until then Phenom 2 will be in mass production for a good year or more.
RIght now Intel will be selling VASTLY more 45nm chips than 32nm. Sandybridge is new, i7 hexcore stuff is the only other range of 32nm things, i7 quads, i5 750-760 all 45nm and in mass production but that be winding down. i3's are 32nm which are winding up. When they bring out 22nm stuff early next year, it again will be 10% of what they sell. Hell, Intel will release an entire new 32nm octo/hex/quad core LGA 2011 range for desktop and servers only weeks/months before 22nm hits.