I can only hope that w7 will be the last os for quite sometime....i mean look at the gap between xp and vista..huge....... if ms again comes out with another os next year.....ill be throwing up my hands.....i certainly cant afford a new os every year or so.....its unfair and i think nothing more than a scheme for ms to make more money....... *grrr*
Well Windows server 2003 came out right after XP. So I wouldn't be surprised if there is a server version to be released within a year and do not count that as a new OS.
If you count NT/2000/server 2003 as its own string of OS's seperate from windows 3/95/98/ME/XP then the average is 2-3 years between OS versions (they are 1992/1995/1998/2000/2002 respectivly) I expect this that Windows 7-8 gap will be the same 2 years. Initial versions of Longhorn (that became vista) came out in 2005-2006 again meeting this 2-3 year gap and making 2-3 year to windows 7 still sync up. Just long horn wasn't remotely stable until 2007 when they FINALLY made public release. However you see the link is still there. 2000 (me) > 2001/2002 (XP) > 2005 (Longhorn: Not released) > 2007 (vista) > 2009 (win 7) you still have a fairly consistant about 2 year gap between OS.
Alternatively, the initial versions of XP came out in 2001 I believe (as I just looked it up. I remember it being 2002, but so goes memory), meaning that the ME-XP gap could be said to be 1 year, which would be similar to Vista (spring 2008)-Win7. ME was something "new" and XP was this same idea "but done right". If it follows the ME to XP/ Vista to Win7 tradition then we won't see a WIN 8 for like 4 years, and it will suck. Then WIN9 will come out about a year later and be good.
EDIT: -the point is not to growl an MS for releasing on a schedule. Its not JUST a scheme, they follow a fairly consistant development cycle and since I don't see longhorn on my system (or any other) they obviously arn't so stupid to release unless they think its something worth releasing. As a tech-support agent, I defend vista for being much more stupid-user friendly and was a very good step in the right direction. I don't use it myself, but I feel that most of the changes it makes are very logical and the new interface I think is an improvement if I can get over the fact that "its not like it used to be"
My favorite quote on that "Just because we've always done it, doesn't mean its not stupid". Vista was an attempt to fix something broken (office is a better example, the classic file/edit/view toolbar is dumb / out of date and should be done away for something better )