always wait. It's the internet version of the FASTEST. The longer you wait, the faster your question will be solved with processing power. They want you to buy old tech, no...wait, buy last years tech. There has been improvements, their search engine hasen't returned results. The longer you wait, the more the next technology will seem like an improvement. These guys will tell someone who has a AMD 7950 to wait until the 8930 to buy. Buy what you need. Newer is better, but the internet stays the same.
Reality: Buy what is fastest and within your budget at the time. I didn't really need to tell you that, did I? Fine, consider this research and ask a more specific question about processors.