I think both (just to be a pain of course! lol) 

'What is he doing?' reminds me who is no. 1; what i'm really here for; that he is definitely active; and just makes me wanna fall to my knees and thank him - which i think's awesome really, especially in a world where it's very easy create your own bubble sometimes. But is also shows us where he isn't, and 'what would he do' seems to be a natural question to follow because it doesn't let us stand still - it looks to bring more of him into everything.

hmmmm.

actually, now i think about it ... if i had to choose between the two ... it'd definitely be 'what would he do' - cos the other question leaves me thinking i have no responsibilities to be doing the DOING. dunno if that makes sense! haha

Well, I never could work out what was bothering me about those WWJD bracelets it was so cool wearing when I was at uni (kinda puts a house number on me - doesn't it?).
Then I got to thinking: If I was just thinking about what Jesus would do, it's like I'm thinking of a dead person who can really still inspire people: then I might as well ask, "What would Ghandi do?" or "What would Bhudda do?".
But having been to some pentecostal meetings in my life, where things happen you just can't explain (!!!), it kinda started feeling more appropriate to reformulate that question. It makes me want to spend time with Him really trying to get insight into His modus operandi.
I also think He's very interested in what we are doing now. I can't imagine Him just fidgeting around on the edge of His throne waiting to collect His bride. My experience also tells me differently.
Funnily enough, it even makes me keen to look at what He used to do when He was living on earth. Peter wasn't asking "What would Jesus do?" when he climbed out of that fishing boat in the middle of the raging sea...