Whoops - I see that your employer sponsored you. I would recommend that you continue with your present employment for at least 60 days to avoid immigration problems in the future.
Extraordinary Ability requires no employer to file on yur behalf. Despite this, an alien has to have had the intention to remain in the field of endeavor for which they sought extraordinary ability classification. Thus, if you change jobs, it should be to one in the field of endeavor. I do beleive there is some confusion as to whether your employer filed the extraordinary ability petition or if you self-filed. Who signed the I-140? If the I-485 has been approved, you should expect your lawful permanent resident card to arrive in approximately 2 to 4 weeks.