I would try to reset the light and disconnect the battery for about 20 minutes and see if the idle is still rought (same as before) with the MAF connector unplugged. If this is the case then it could be several possibilities. One being the fuel filter if all hoses check out...make sure none of the hoses got blown off, including the charged air hoses to the turbo (one being on the driver's side at the bottom next to the radiator (90degree 2.5 inch diameter hose). Also, it could be that your throttle needs cleaning badly or you're experiencing some electrical issue such as bad igintion wires. If the car idles fine (still will set the MAF light if it's disconnected), then it really is your MAF.

I just went through this recently with my S70...but disconnecting the MAF connector let the car idle without bucking or dying, but as soon as I connected it up, my car would die, so I replaced it. I didn't have time to dilly dally around, so bought one from my dealer...a $205 part, but they gave me a discount and I got it for $177...still high. www.fcpgroton.com has the Volvo part for about $168...and after market part for about $20 less. You might also check some salvage yards. I could have bought one that would have worked on my car for $60, but I wasn't sure it would really fit, so I passed it by, later to find out it would have worked fine. Anyway, good luck with it and report back what it was.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.