To be honest, I got a bit confused with the various 64-bit CPUs (like why didn’t Intel and HP’s Itanium take off, but AMD’s AMD64 did and Itanium 2 looks like it will too), but whatever the hardware issues, it seems that x64 software has finally come of age. Paul Thurrott reports in his Windows IT Pro magazine network WinInfo Daily Update that, at the IT Forum this week, Microsoft announced that the Longhorn Server wave of products will be 64-bit only (except Longhorn Server itself, which will be available in both 32- and 64-bit flavours). That means that, for example, the next version of Exchange Server (codenamed Exchange 12) will only run on a 64-bit platform. There’s no news yet as to what is happening on the desktop (except that it seems, like Windows XP, Windows Vista will be available in both 32- and 64-bit editions) but it looks like I’d better get saving for a new PC…