is skylake good for gaming

Thats a very general question.

One answer is "Yes! It will be awesome!". And then you could buy a Celeron and be disappointed.

Another is "NO! Its a piece a crap!". And You would buy an i7 Extreme Edition and be overly surprised.
 


Skylake will include product refreshes for the Core i5's and i7's. Those will certainly be fine for gaming, just as they have been for years.
 
Skylake is simply the group of processors being released, not a specific chip. There will most likely be one for around $1000 that will run any game released on the highest settings for the next 5 years, and there will probably be a chip that will run current games on medium.