The Intel P35 chipset is most likely going to appear before its official launch at Computex in June. The latest main stream chipset from Intel with DDR3 memory support was originally scheduled for review release on the 21st, but this has apparently been pushed forward until the 9th of May instead.
Boards should also be available in the retail channel ahead of Computex, which is on the 5-9 of June this year. We would also expect to see other chipsets arrive around the same time, as it doesn't make a lot of sense for Intel to launch a single product, although considering the problems it had with it's G965 chipset, Intel might just stick to the launch schedule of its integrated graphics parts this time.
P35 can also support DDR2 memory and there will be DDR2 / DDR3 combo motherboards as well. We are still not sure how well this chipset will overclock, but we expect a lot from it.