Query on H1B petition duration & H1B transfer.

My H1B petition for FY13 got approved back in Aug & I was suppose to travel to US by mid of Oct which later got pushed back to start of Dec. But due to some reasons, the role got scrapped last moment & employer don’t have any opening as such for the time being for me to fit in. My visa stamping not yet done, as par company policy it’s done based on the availability of a confirmed US role & before you fly.
So my question to this forum is:
1. For how long an approved H1B petition stays valid, say in my case?
2. Can we transfer H1B to another employer with just an approved petition, again like in my case if I want to switch to another employer? If yes, what all informations I need to furnish to the other employer to execute this transfer?
Thanks for the help.