Waiting to upgrade really doesn't make sense in most cases. There will always be something better on the horizon. If you see something you like now, go for it.
Based the needs you outlined, I would suggest the X6 1055T ($200), the 1090T ($300)or the I7 980X ($1000). Not only do this three chips best fit your user profile, but more cores is always better in the long run. 4 years from now, you will be glad you went with 6 cores.