When would one predict the next generation of Intel processors will be released?

Is there a time frame (every 2 years during the summer time, for example) when Intel usually releases new processors?

If someone asked you when new 2012 cars come out, people who know cars would say spring-fall 2011. I'm seeing if something like that works for processors, too, and if it can be approximately predicted about when new processors may come out.

Thanks :)