Hmmm Ginnu, thanks for the answer - its a little difficult to digest, because I just didn't know this. So to put it into perspective, a couple of questions:
1. You mean I could be laid off from job, and stay jobless, for as long as I-485 does not get adjudicated?
-------------------------you need job offer at the time of I-485 approval and much better if you get job before the I-485 approval.
2. What happens to my I-94 in that case?
----I-94 has nothing to do with I-485, your I-94 is based on H1
What if it expires?
--------------------------you are pending AOS status and for work you will need EAD in Hand and if you go out US you will need AP filed IN US while you are in US and approbed in US Before you go out to use AP to enter US
Can I renew my I-94 simply on the basis of my I-485 being pending?
--------------- you cant RENEW I-94,your employer need to file H1 extension BEFORE the I-94 gets expired and will get new I-94 with H1 extension approval notice
If so, for how long do I get the I-94 renewal for?
------------------read above
3. As is the case for most recent I-485 applications, because of their very recent PDs, their adjudications could be years away. So you mean somone could just get laid off, and sit tight and if he can, and time getting a new job so that he has a job or a job offer just before the time of adjudication?
-----depends on case if approved I-140 is not revoked before pending I-485 hits 180 days
Appreciate your taking time and effort to answer the questions.