1) The Judy is an okay fork, but heavy for a weight weenie (myself included). You can lose 1 to 2 lbs. switching to a Manitou Mars or Rock Shox Sid. Keep in mind these are XC race forks with 80mm of travel. ($250 to $600)
2) Your Deore mechanical discs are notoriously heavy, but reputed to be good stoppers for the money. Switching Avid mechanicals will save another 1/2 lb. Going all the way to v-brakes, which would require rim changes, would save 2 to 4 lbs. ($200 to $300).
3) 14/15 DB spokes with alloy nipples make a huge difference in rotational weight. ($100)
4) Even though the XT crank is lighter, the XTR bottom bracket is much lighter than the XT's. Therefore, the XTR crank/bb combo is lighter than the XT or LX. However, XTR is much more durable and stiffer than XT/LX.
5) Don't compare your Raleigh frame to a Trek 9.8, Cannondale CAAD5, Specialized M4 or some other high-end racing frame. The M600 is a great value and reasonable trail bike, but it's frame is, most likely, 1 to 2 lbs. heavier than upper end hard tails.
6) Are your tires kevlar bead? There can be as much as 100 gram difference (not quite 1/4 lb.) between the kevlar and wire bead tires of the same type. Switching to a 1.95" kevlar beaded lightweight could knock off another 1/2 lb. ($70)
7) Switching saddles - Selle Italia Flight TT - 165 g. 1/2 lb. savings. ($70)
You'll spend hundreds - maybe a grand - to get to 25 lbs., and you may have to swap out wheels and go to v-brakes to get there.
I spend all last summer upgrading a Raleigh M80 that I raced all season. By the end of the summer I had a great bike and it weighed in at 25.5 lbs. Only the frame was stock. Then I upgraded the frame to a Giant NRS and only added 1/2 lb. FS and only 1/2 lb! The Raleigh frame was stiff, but not light.