Try this...
http://www.immigration.gov/lpBin/lp...-21?f=templates&fn=document-frame.htm#slb-act
The Immigration and Nationality Act (with AC21 applied) has sections added for Labor Cert and I-140 remaining valid after the 180 days mark if the job is same or similar. These are 2 separate sections of the INA act, therefore both are mentioned in AC-21 as the AC21 provisions had to be added to 2 places.
The point about Labor Cert and I-140 both being mentioned is that if you need both, like H1Bs do, then both have to remain valid when changing job for AC21 to work. EB1s do not need Labor Cert so the section about Labor Cert is irrelevant.
There is nowhere in this section of AC21 or the implementation in the INA that says it is only for H1Bs. It only ever references EB, employment based.
It is true that the AC21 act was aimed at H1Bs but one of the few sections of the act that does not explicitly mention H1B's is the section we are talking about.
The law itself is pretty explicit, except for the comment in 204(j) about subsection (a)(1)(D) which makes no sense!
The attorneys everyone has spoken to have probably not all read either law. Neither have most immigration officials. That is why we are bound to have the odd problem. If the approval of EB1s using AC21 was a big no-no then I reckon they might have mentioned it in the August memo. Anyone who is rejected under it would have a decent reason to challenge that.
Please note that this is just my interpretation and if anyone reads the law differently, I would love to hear it as I am EB1 and need to use AC21 very very soon (I have no choice!)