People will GAIN space - some have claimed they got 28GB back. They really got more like 7 or 8 free for real; it says 28 because Apple changed the algorithm to what hard drive companies use to calculate gigabytes. (yet tart magazines like zdnet say that was a bug Apple "fixed". zdnet has "good OS envy" which is why half of them bash Apple for every little nitpick. Ironic as, in this case, Apple was going from technical correctness to using the same wrong calculation hard driver manufacturers use...)
http://blogs.zdnet.com/storage/?p=589(will use "80" as a generic HD capacity figure)
1024 * 80 = 81920
1000 * 80 = 80000
The remainder, 1920, is seen as (almost!) an additional 2000K by the new computation. That's why people think they have a lot more free space.