I know this is mostly a forum about money -- but sidenote: I've never understood why management does things like this. Watch the bottom line, lay everyone off, then scramble shortly afterwards to fill everything so nothing misses a beat.
They've been doing it in my job area (offshoring -- and they are very upfront about it) but with the 'pre-notices' for layoffs, people jump ship faster than management would like, so there's no training for the 'offshore' person. You can imagine how well that's going over with the rest of us 'onshore' folks right now -- trying to cover the jobs, reports, figure out who did what roles, who you're supposed to send things to, etc.
They did this to a former co-worker of mine in a prior job, too. Loaded her up with work, had her train new people under her, drove her to quit (by offering someone way below her / newer more than she was making), then immediately called and tried to make a better salary offer to come back. She declined -- said the fact that she finally got to stop taking anti-depression medication was worth more than the mini-raise.
If you've got the skill where they NEED you to stay around, use that leverage. Keep in mind, they (mgmt.) probably just saved a boatload of money from salaries, benefits, etc. so it's not like they're short on cash. See how bad they need you, then decide if you want to stay. Keep in mind, the more you ask for, the longer they'll probably expect you to work (at which point I guess you can just leave on your terms).