Would it be worthwhile upgrade to change from MSI K8N neo4-f(no OC potential)+3200 s939 to DFi nf4 ultra-d + x2 3800 for $275? with prices so low on x2's I'm really tempted to buy and OC. I realize that the performance increase even with OC will not be much but dual-core should matter right?? changing to AM2 is not an option cuz I can't spend $$$ on DDR2.

I would recommend saving your money and buying an AM2 or Conroe system, I don't know how much RAM you have but for around $200 more you can get 2 GB of good DDR2, and buying a new 939 mobo right now is really just a waste of money since new chips will not be available for those sockets anymore.

But if you have your heart set on upgrading, I think it would make more sense to simply keep your current mobo and buy a $275 chip unless your current mobo has problems other than OC'ing or the new mobo has features you want.

I say go for it, because X2 is the way to go right now you will see a performance boost when you are bugged by a anti virus program.
Go for it I went from a 64 3200+ to a X2 4400+ and what a difference.

dmantech: Zone Alarm is actually the problem that made me want to upgrade cause program load time increases with each ZA update.

Well, if i do save my money for a conroe or K8L, when can I expect a mature platform(mobo support)?

Conroe should have mature mobo support in just a month or two. K8L will have to be finished first but it will probably have mature mobo support shortly after it ships.