90% of what is done on my PC's by my kids and myself is either playing games on NeoPets or Cartoon Network (So Flash and Java are a must.) or writing music with Cakewalk. (I used to use ProTools on the Mac until I lost my copy.)
So if I can surf, do Email, play online games and write music... then 90% of my Computing needs are met. (The other 10% would be playing Blizzard games like Diablo2 and Warcraft III.
Is that all you want?
Sorry you're SOL on practically everything you mentioned.
There's no java support yet.....although there's a Jamiga effort.
There's definitely no Flash player, and even if there was it'd be clunky like Linux.
There's no Cakewalk port, but there are sure to be some 68k midi composition programs out there somewhere. Maybe someone's working on a PPC one right now. The only music related thing I've heard about for the PPC is Audio Evolution, and I may be wrong, but it looked to me like a sample based program.
Diablo II and Warcraft III?
?? These are recentish PC games right? So its unlikely there'll be a port unless they are released as open source.
There is some hope on the Flash and Java side although nothing has been announced. AmigaDE is a technology being pushed by AmigaInc that is certain to make its way to OS4 at some point. The AmigaDE tech is based on(or perhaps rebranded) Tao's Intent technology. Tao also has a browser called Qi, and Qi is said to feature Java and Flash functionality(at least its a stated goal on their website). Now, if AmigaDE is going to make it to OS4 it stands to reason that Qi will also. But there have been no announcements to confirm this. Genesi will probably buy the tech from Tao for use in MorphOS, in the end as well, if AmigaInc get out of making the port of AmigaDE that a recent court case was about. Yes, its complex and its not black and white, but red and blue. ;-)
But don't hold your breath for any of these things. You could be waiting for a long time.