is it worth it processor wise?

my specs

amd athlon 64 x2 dual core processor 4400+ 2.3ghz
3gb ram ddr2 sdram
sapphire HD4650 1gb
motherboard

Would it be worth it to upgrade my processor to a AMD Athlon II X2 250 AM3 3Ghz 2Mb? Would it work seeing i think my motherboard is AM2 and the processor is AM3?

If it wont could anyone recommend a decent processor?

thanks