Last week Apple licensed Activesync from Microsoft, according to a source very deep inside Microsoft’s Exchange product team.
While Apple’s iPhone currently supports Exchange via IMAP, it has not made any announcements about Activesync per se. Further, if Apple does implement the bits, they may opt only to utilize messaging (rather than tasks, calendar, Direct Push, etc.).
Given the cost to get the Activesync license (which is rumored to be over 7 digits just to get in the game), it would surprise me if Apple doesn’t implement at least some of Activesync’s capabilities into the iPhone, although this will most likely come as an “update” or on iPhone v.2.