Yes, it's true. All the benchmarks say that Intel has finally caught back up to AMD. Actually, some of their latest P4s before Conroe were at least acceptable, though you still benefitted a bit more from a high end AMD in certain things. Conroe, however, means AMD has to do something and fast because it's doing games and everything better as well as being efficient with power and such (one key feature of Athlon 64 was that it was built on mobile technology, so the extra power saving and other such things built in meant it ran cooler and more reliable than later P4s, but, here Conroe has caught up as well and Intel users with these I think won't be having to worry so much about their CPU shooting up well past 60C all the time like they have to with Preshott and co.)
Actually, from what I hear, Intel isn't really doing so great and those chips wouldn't normally cost so little, but, they are trying to wage a price war. They can't be operating at a loss though as that would hurt even worse, so I'd say maybe grab them while they're hot as they may go up later, but, I could be wrong (just a guess here.)
As for whether Conroe is a DOSBox dream or not, I'd say it's probably still not powerful enough for the REALLY heavy games (maybe stuff like Tomb Raider?) but, having seen what my 2.4GHz San Diego can do (think Athlon 64 4000+ as it's essentially the same thing) I'd say that by looking at how far ahead the Conroe is, the list of games that won't run wonderfully on a good Conroe core chip is probably pretty small (I'm already able to play some games surprisingly more complex with this chip than I expected I would see, and they run pretty smoothly.) Then again, AMD must have something up their sleeves. (For example, I've heard they have a technology in the works to make multicore/smp processors show up as a single core to things so that, in theory, you actually get the combined capabilities of both cores rather than just a small added boost like you currently see. By the time this comes out though, games may finally be as multithreaded as they really should have been for a while now.) AMD just snatched up ATI for some reason, I wonder if they plan to try to integrate some sort of video technology somehow to make them better at gaming? Either way, Conroe will still be ahead for something like DOSBox if they change nothing else I think.