One thing that stands in our way, of course, is the stupid Penn Treebank, which was annotated only with very simple transformations (mostly noun phrase movements) and not really "deep" transformations as most Chomskyan linguists would recognize them [emphasis added].
Oh no he di'nt!
[UPDATE: hal responds thoughtfully in the comments and properly corrects my misunderstandings of his post.]
It's certainly fair to say that the Penn Treebank is not annotated for everything. Sure. But show me the perfect resource and I'll let you throw all the stones you want. More to the point, once you get beyond deciding what the basic chunks are (NPs,VPs, PPs, etc), there's little agreement on what is and what is not a "real" syntactic thing. In order to annotate anything above this level, you have to choose a theoretical camp to park your tent in. You have to take sides.
In order to annotate Daume's
Daume may believe that Chomskyan theory is "real" syntax, but I do not. Nor do most linguists (if you surveyed all linguists throughout the world, yes I do believe a majority would disagree with the statement I believe in Chomskyan deep structure).
UPDATE: Daume's comments and his responses are well worth reading.