Interesting developments! My read: the exec producer credit is usually taken by someone who oversees or owns some stake in a project, but isn't deeply involved in day-to-day production. In other words, that credit suggests strongly that Jackson won't direct.
All the information coming out right now -- and for the next few months -- should probably be taken with a grain of salt, but according to
this Entertainment Weekly article, Jackson's manager is saying he definitely will not direct.
I'll bet you'll be able to get a good gauge of how hands-on Jackson will be by the director they ultimately select. I can't imagine some of the bigger name directors whose names are being slung about being willing to just come on as a workman to execute Jackson's vision. There'll be more of a partnership there if you hire, say, Sam Raimi, mark my words. A lesser-known protege, like Neill Blomkamp, the guy who was supposed to helm
Halo, might indicate a more hands-on approach by Jackson.
The article implies that Jackson's writing team won't be directly involved either, which is good or bad depending on your point of view.
As far as content, I can't imagine they'll come up with a complete film from whole cloth of the time between TH and LotR, as some reports suggest. What is there to do? Show Bilbo using the ring to hide from neighbors?
I expect a beefed up
Hobbit in two parts, with every off-screen action or backstory element you can imagine dramatized -- Smaug's original attack on Lonely Mountain as a prologue, maybe Gandalf retrieving the map and key from Thrain in the Necromancer's dungeons as a flashback somewhere, and so on. And of course battle sequences drawn out for maximum effect. There's plenty of material there for a couple of two hour films, I daresay, though I haven't read through
The Hobbit in a while. This is a good excuse for a re-read!