An interesting part of the pitching experience that, in retrospect, should have been ultra-obvious was the question I might get asked. I didn't consider it much before-hand--combination of nerves and other fish to fry, such as nailing down the essence of my story.
But questions were asked. Some I fared all right with, others I muddled through. This is clearly not the list to end all lists, but here's what I was asked:
Stand-alone vs. series--This fell into the easy-to-answer category, and is particularly relevant to sff where long epic sagas proliferate--especially unpublished, long, epic sagas. My answer seemed to be what they wanted to hear: stand-alone, with potential sequels. Although a series can get sold, it means convincing someone to fork over for not one book, but three (and I hope it's only three for your sake). Better to hit them hard and leave them wanting the next installment.
What books would you compare it to?--This one nailed me. I've thought about it before, but never come up with a compelling answer that I feel captures the style and world of my book. It wasn't a deal-breaker, but I sure didn't feel sharp scraping my brain on a moment's notice for something intelligent to compare it to.
Earth-based vs space-based?--This actually highlighted in my first pitch that my setting wasn't crystal clear. Especially if you are working in an alternate universe, grounding is important. I filled in at the time and made more direct references to locations in the later pitches. I definitely recommend listening carefully to what's being asked, though, to see if it signals something you should have given in the main pitch.
What's the ending?--I actually had some preparation on this one since my pitch leaves it hanging. No one asked directly, but my friend Heather has been asked it in pitching before. I'm glad I'd considered how to succinctly answer that because otherwise it would have been easy to blather.
Where can we back up the truck-loads of money?--Haha, just kidding. Certainly didn't get asked that... at least not this time around :)