Should you wait? Short answer: If you want to.
That's a question no one can really answer yet. The skylake processors will have a better performance, but that doesn't mean the current processors aren't great. If you want to wait for an upgraded processor then waiting will be worth it in the long run. However it might be awhile before Apple updates its current line of MBPs, probably mid to late 2015. Personally, I won't be waiting. The current performance of the MBPs are great, good enough for me at least 🙄