I just finished 6 years on H1B and recently got 3 years extension (based on approved I140 in EB2 category) for a H1B visa valid till Dec 2014. I am from India and do not think I would receive green card in next 2-3 years.

I plan to change my job in May 2013 to a different firm, B, for better career growth. Would I get a H1B visa for renewed 3 years from that time (from May 2013 to May 2016) for firm B OR do I get new H1B for remaining 1.5 years only valid till Dec 2014? Please assume my current firm, A, would keep my I-140 till June 2013 after which they would withdraw it as I would have left the firm A.