Microsoft’s announcement today that it would keep Windows XP (Home edition only) available until June 30, 2010 — not June 30, 2008, as originally planned — for the emerging class of ultra-low-cost PCs (ULCPCs) is the second crack in the wall in Microsoft’s pig-headed insistence that it will stop selling Windows XP on June 30, 2008.The first crack was when Microsoft committed last year to keeping a “lite” version of XP, the Windows XP Starter Edition, available for PCs in Third World countries for the forseeable future. The ULCPC and Third World decisions have the same rationale: Those computers simply cannot run Windows Vista, not even the not-really-Vista Home Basic version. This puts developers in an awkward position: To support these markets, they now must continue to invest in XP-capable software, yet the markets where they’ll make real money won’t have new XP computers to sell their wares into. So what’s the incentive to develop for the ULCPCs and the Third World? None, really. So what will these computers run? I expect to see a big market in recycled software.The glass-half-full theory, bolstered by lots of rumors among journalists, is that Microsoft will at the last minute extend XP’s life another six months or so. But that won’t really address the market issue Microsoft has created by keeping the new-XP-user market unlucrative. The glass-half-empty theory is that both the ULCPC and Third World PC markets are unimportant, serving just poor people, so Microsoft can make the XP concession to them without getting in the way of forcing Vista on people who have more money to buy the requisite new hardware and app upgrades.Either way, the glass is half full. Microsoft can fill it by keeping XP available, and thus keeping the XP app market chugging away even as it continues to promote the Vista market. That’s not ideal for Microsoft, but it is for everyone else. Technology Industry