I'm not sure about the trial version of PE7, but the trial of PrPro C4 does not contain any MPEG CODEC's at all. This is due to licensing with MainConcept. Adobe would have to pay a royalty for each free trail version, so they omitted these CODEC's. Everything else still works, just nothing MPEG.
I know the trial versions of PE used to watermark any output, but wonder about the MPEG CODEC's, as they would have to pay royalties to MainConcept for PE too. I have the link on the info covering the PrPro trial, but could not find any for the PE trial. Someone with direct knowledge of the PE7 trial will have to confirm, or deny, my suspicions.
Out of curiosity, exactly where are you looking for these Export settings?
They were on the right - one of the coloured tabs e.g. GET/EDIT/SHARE etc. But it's alright though I've found that Premiere Pro does the job well enough
Great. The full-paid version of PrPro, as of CS3, will do a very nice job. CS4, as of the 4.1 update, does even better.