First, lets look at some raw physical measurements...
6-3, 250 (nice)
4.7 forty, 1.55 split (explosive)
38" vertical (explosive)
6.66 3-cone (excellent for a pass rusher, very good change of direction)
31.75 arms (kinda short)
The raw data seems to indicate a physical ability to be an explosive pass rusher. The short arms are worrisome, but his get-off and ability to quickly change direction compensate for that.
Next, lets consider his instincts and intelligence. Only the Dolphins' wildcat and Tebow's spread option have enjoyed continued success at running option football in the modern NFL. Other teams (Jets included) have run some option here and there every now and again. But it takes a special blend of instincts, intelligence and athleticism to run option over and over and over again with success, and when everybody knows its coming. That feel can be used on defense too. Tebow is smart enough to check himself out of an edge blitz and drop into zone where his presence will be disruptive. And he can read a protection scheme and change directions to find a hole for a sack just like he could do when he's running the rock for a first. That ability is unique, and it could be deadly if used on the dark side. I could actually picture Rex throwing Timmy in at backer on 3rd and long and letting him free-lance it. He could show blitz and drop into coverage. He could show blitz in an A-gap and loop on a stunt around the edge. He could jump into an overload on the edge at the last second. He could do some damage.
Lastly, lets face it... this is a brilliant idea. If Tebow somehow became a successful two-way player EVERYONE will go freaking GA-GA. He'd be the complete throwback folk-hero everybody wants him to be. And he'd have a justifiable reason for being a novelty. Timmy Two-Way with the reverseable jersey. A true quarterback of the offense and the defense. He'd be even more of a marketing machine than he is now.