Funny Blaze and you should bring this up considering just before WMX8, Off the Record had an interview with Flair and one of the questions that Michael Landsberg asked him was "Do you think we'll ever see a revival of the Four Horseman again?" Flair's response was something like this :
"Well I'd be lieing if I said I didn't want to see it. I'll tell you right now, there's 4 guys in the WWF that I can definitely see forming the new 4 Horsemen."
Something to that extent
Anyways, if they do reform, I'd say :
Definitely
Chris Benoit
Kane or Bradshaw (I mean Flair didn't say Kane would be an integral part to oppose the nWo for no reason and there's your enforcer.)
Stone Cold
RVD
Flair will probably ask The Undertaker to join and get his ass kicked for it

. The manager could be Flair or Anderson but maybe it could be Shawn Michaels

.