Build new PC in the next few weeks or wait for the next gen of process.
Which do you think would be best
To give reasonable advice, we need more information.
What is your current computer configuration?
If you currently have a 5 year old computer with something like a Core 2 Duo
E6600. my advice would be to go ahead and build a reasonably capable new computer that will last you 3 to 5 years. On the other hand, if you already have a i7-2500K and two 570 in SLI or two 6970 in Crossfire, I would wait for the next generation.