You're about to reimplement every tool that somebody would want to use to set up a landing page, beginning with an editor. What if I want to use a wordpress blog as my landing page. What if I wanted to embed the launchrock lead gen tools with some announcement that is posted on another site? I think that'd be useful and you wouldn't have to build so many things.
Ouch. I understand there is a large amount of technical work involved in getting everybody transitioned over smoothly, but you'd think they'd get the current customers ported over first, instead of driving off without them and promising they'll be back to pick'em up soon.
What are we supposed to do once there's a sizeable email list?