Here's why rebooting Blofeld won't work. Unless you intend to remake OHMSS then there's no point building him up. Might as well re-tie the Craig chronology into the old series. Blofeld's main selling point was that he was the guy who would kill Bond's wife and then he became the guy who did kill Bond's wife. (Let's pretend Irma Bunt isn't holding the machine gun, of course.) Without either, there's nothing special about him, and no reason to re-introduce him, other than,
A) The Persian Cat
B ) Bond fanboys will spray their shorts to see him again
C) Austin Powers's own Dr. Evil
So either he's the guy who killed Bond's wife or let him rest.
Enough of the reboots.
Agreed.
If EON wants to (and I believe that they should at some point) revisit the Tracy storyline from On Her Majesty's Secret Service, then that would be the only circumstance under which I'd be willing to see Blofeld return. Assuming they don't go that route, then what exactly would the point be, other than to give Bond a villain with some built-in name recognition. Just go ahead and make an original villain and actually put some thought into making him the biggest and baddest villain Bond's ever faced rather than taking a shortcut to accomplishing that by giving him the name Blofeld.