After months of speculation — capped by a flurry of rumors over the past 10 days — Comcast’s new NBC U structure is expected to be announced this week.

But that won’t be the end of it. What we’ll see is the “beta” version of what the newly merged company will ultimately look like.

That’s partly because of the timing. With NBC currently in the middle of development season, incoming NBC entertainment topper Bob Greenblatt won’t necessarily be looking to make changes too quickly, at least on the programming side.

There may be other arenas where he can make his mark first. (New ABC Entertainment topper Paul Lee has taken a similar tack over at the Alphabet net.)

Meanwhile, with regulatory approval still on the horizon, there are many moving parts yet to be determined. That’s why many folks inside NBC Universal expect a second, more comprehensive restructuring at some point in 2011.

While former Showtime Entertainment prexy Greenblatt’s hire has been assumed for some time, speculation heated up over the weekend that Comcast Entertainment chief Ted Harbert may return to the network game.

To further illustrate how fluid the situation has been, Harbert has, in the past few months, sometimes been talked up for a major role at the merged company; at other times it’s looked like his job wasn’t changing.

But Harbert is now being bruited as a frontrunner for the NBC business/operations job. Comcast had also approached CBS’ Nancy Tellem and Fox’s Tony Vinciquerra, among others, at one time or another for the gig.

But Vinciquerra quickly declined, while Tellem, who formerly had oversight of entertainment at CBS, wasn’t interested in a job with a smaller domain than her old one.

With it looking increasingly likely that Comcast Entertainment networks E!, Style and G4 will be split between Bonnie Hammer and Lauren Zalaznick (both of whom are keeping their current domains), it probably made sense to find a new job for Harbert.

Harbert hails from the entertainment programming world, having served as president of both ABC Entertainment and NBC Studios. But as CEO of Comcast Entertainment, Harbert’s focus has become much more business oriented — making him a possible candidate for the New York-based job (which has been compared to the NBC TV Network president job once held by Randy Falco and Neil Braun).

NBC U TV topper Jeff Gaspin remains a wild card, as the exec has not yet been informed of his fate.

As previously noted, incoming CEO Steve Burke is set to meet with execs this week in Universal City to iron out the new setup. An announcement could be accelerated to as soon as Monday, perhaps to quiet all the incessant rumors.

At NBC, this week’s announcement will, at the very least, make it more clear who’s in charge. But there’s still much more to come.