There was a different heatsink, and shrouded fan as well. If you're not getting those items, price them out before buying.
I think the better upgrade path is to get a QS processor that has the L3 cache. I've been running a 933mhz in my DA for almost two years. It's quite a bit faster than the DA733 (which only had 1mb of L3), and I haven't had to put another fan in the case.