I think that Jobs has a reality distortion device that he uses to make time slow down as we approach the expo's. He also might use that to speed up the developements to get the items ready, but then has to wait for real time to catch up. If he wanted, I'm sure he could loan the device to either moto or IBM to get them to speed up production (to reduce cost) or development of the new processors. Properly implimented, we could have the G6 out by now, instead of waiting for the G5 with baited breathe.
It also could be that he puts teams heavily into certain projects that he wants finished before something else is either started or worked on. Then when enough is ready, the announcements come out. Two major updates/announcements per year is not too bad, although I wouldn't mind seeing more.
As for microscrew, consider this, they plan on one release/update every 18 months. Items such as office and windblows fall into that category too. They seems to work a little faster on ie, at least on the peecee side, but not on the Mac side (those bastards).
btw, this looks like my 1k post... finally broke that barrier, now to set my sights on the 2k mark. I know that at least four of the regulars here will get there before me (like eyelikeart). Maybe we should start a 1k post club

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Rock on, and I CAN'T wait to get my TiBook back from Apple (hope to see it by Wednesday).