If it ever came to be than I'd have to say that Brian and Roger are the mental cases. They honestly can't be that desperate to perform with him after that last horrific display!
"“We will definitely perform together again,” said Lambert. “Standing in for Freddie [Mercury] feels natural for me.”"
Handling this with sensitivity could be tricky, Brian. I suggest you pretend that you lost his phone number. If he calls you first, make *krrshshshs* noises and say 'sorry, going through a tunnel'.
Somebody should get Tim Staffell to crawl out of his obscurity cave and have him reunite with Roger and Brian so they can do a new Smile album - it would be the nearest thing to Queen possible, so I say GO FOR THAT IDEA!!! Plus, that way, Deaky can stay comfortable in his retirement (although where he lives is unknown because he won't drop anyone a single line) knowing he composed some of Queen's greatest milestones - YMBF, AOBTD, IWTBF...
Another Q+PR tour would be good enough for me, or even just Roger and Brian touring (with the backup band). Deaky doesn't look like he's ever joining them again so that's a bit much to hope for.