I like the bookmark idea, but in the heat of battle it'd be hard to remeber "oops! better save!" I'd rather they implement a option for saving every 5 minutes during the skirmish so you could at wors have to replay 5 minutes worth before getting to the critical point.
Hate to be the goodie-goodie, but someone should continue this in public suggestions. It's turned into a major suggestion type thread, hasn't it?