Microsoft's Next Operating Systems....Fiji and Vienna

Hi,
After 5yrs gap Microsoft released Vista(former name:LongHorn) , After clearing lot of bugs in the operating system, finally they released & made ramarkable mark of selling 5 million copies from Jan2007.Even i feel it's not a successful Operating system..........
I heard it contain lot of bugs even its release.Its common.

Now microsoft announced there next Operating systems to be released quite soon, might be in 2008.
They are Fiji and Vienna..............