They are including XP because many business use very old legacy productivity applications that have not seen updates in years, and are incompatible with anything newer than XP
they're including XP because many enterprise users realized that Vista was junk and refused to "upgrade" to microsoft's new OS. microsoft is hoping to trick the enterprise user into believing that 7 is not Vista related, even though it's exactly what Saul said it was a few posts back- a rebranded Vista that now has the ability to appear like the OS they're used to using.
if i'm an enterprise user why do i need my productivity applications to be compatible with anything newer than XP? you do realize who's fault it is, if my productivity aps are not compatible with anything newer than XP, right? microsofts. MS chose to invent the need for a new OS.
they should have just continued NT's development through XP with their service pack crap & figure out a way to charge people for its development and continued support. instead, they're now launching Vista Part 2. i'm sure the new OS will launch will a lot fewer problems but the whole mess could have been avoided.