H1B Visa transfer

[jackk123]

Iam working for a company X since 2 years. My visa expires in feb 2016 and I had applied for extension in sept 2015. Meanwhile, in Nov I got an offer from company Y. Company Y applied for H1B transfer and got approved. But i changed my mind and decided to continue with X since I knew i would get an offer from another company XX (which is better than X and Y). I now have an offer with another company XX. Now, what are the challenges i would face ?
-- can compnay XX file for transfer with my current I94 from company X ?
-- Is my extension petition from company X still valid ?