The SPECIAL system is rather integral to Fallout. That isn't to say that Bethesda couldn't use the Fallout setting and their own RP system but it would be rather odd. It's also good to try new things and speaking personally there are some elements of SPECIAL I hope they consider for their new Elder Scrolls game (like having a perk/feat/special ability system).
A DIY skill could be neat. I could see it being hard to balance but that isn't a reason not to consider it.
An accuracy skill seems . . . well redundant. accuracy in a weapon is tied to your skill with that type of weapon, having a separate accuracy skill questions what the individual weapon skills would be doing.
A speed skill seems odd, speed feels more like a SPECIAL attribute than a skill. I can't remember if Agility affected your speed in FO3 as it did in the first two, if it didn't then Bethesda should probably consider that.
New Vegas will have a survival mode, if it's popular I bet Bethesda will consider something similar.
I was much happier with Fallout 3's quests so it's hard for me to comment on that part :shrug: