Prospects of David winning a Slam?
Unlike most others, I think David has one of the best all-round games in the sport. Case in point: David's been past the 4th round in all 4 Slams, and is probably the best Latin-Spanish grass-courter today. His serve doesn't have as much power as he might like, but at least it won't record something like 20 double faults in a set or something worse.
But what actually makes David fall short of winning that big prize? It doesn't look like the problem lies in his game or fitness, since he's a guy who's happy to rally rather than go for risky winners. So do you think that it's David's head that stops him from going past all 7 rounds? He came from behind to beat Murray at Wimby, but was also (too) close to beating Hewitt at Melbourne.
If I had to choose, I'd say Roland Garros would be his first Slam, followed by either the Australian Open or Wimbledon.