So Derek and Meredith, as promised and hinted and prayed for by countless fans, might actually stay together. Might, because TV writers are cruel, and there are plenty of potential soap-opera obstacles in their path.

Still, the prospect of hope loomed large in Thursday's Grey's Anatomy season finale, "Freedom." And for Grey's Anatomy - which has ended many seasons by yanking happiness out of its characters' grasp - this truly counts as reinvention.

According to the Boston Globe, reinvention and recalibration have been the recurring theme of this season on ABC, between the Grey's Anatomy mood shift and the five-year time jump that marked the end of Desperate Housewives.

It's an important prospect, at a time when some of the network's biggest hits are showing signs of age - and network TV as a whole is fighting harder and harder for viewers. A hit only deserves to be a hit if it still has the capacity to surprise.

The ultimate model for shifting a series' ground rules, of course, is ABC's own Lost, which has its own two-hour finale on Thursday. Each season, producers have turned the show into a hunt for answers to a different question. Last year's surprise flash-forward - along with the all-important announcement of an end date - did that much to reinvigorate writers and viewers alike.

The Desperate Housewives twist, borrowed from the Lost playbook, didn't feel quite so original. In part, that's because a basic skip-ahead has been done before, on such shows as the CW's One Tree Hill, which recently jumped over the college years, and Alias, which years ago replaced one convoluted plot line with another one.

But the bigger problem is that the Wisteria Lane of the future doesn't look much more intriguing than, or different from, the Wisteria Lane of today. Lynette's kids are young delinquents? You don't say.

Bree as a cookbook mogul? Not outside the realm of possibility. Even the big shocks were fairly telegraphed; Susan winds up with a man who isn't Mike, and Gabrielle finds herself saddled with kids and wearing less-sexy clothes.

And there's no promise of a fix for the show's underlying problem - the fact that it can't decide, minute by minute, whether it's soapy melodrama, dark murder mystery, or broad cartoon farce.

Grey's Anatomy has always done a better job of shifting back and forth between comedy and drama, perhaps because the underlying tone is consistent: hyperactive desperation. Besides, the characters, prone to whining as they are, are generally three-dimensional.

That's why, as each one has sinned herself out of happiness over the years, most of them have grown so unlikable.

The writers have probably been cruelest to Izzie, who, by causing Denny's death at the end of season two, shifted quickly from heroine to crazy woman.

Her adulterous, chemistry-free affair with George did little to help. But as of Thursday, Izzie finally seems to be back on the positive side of the moral ledger book, after proving herself a competent doctor and rescuing the love-crazed Alex from himself.

Callie, often treated so cruelly by the writers, gets a surprising chance at love. The Chief gets to go home. Even George gets a little bit of backbone and the prospect of redemption.

And then there are Meredith and Derek, still star-crossed, still whiny, and yet they've banded together (in a stunningly timely plot) to save brain tumor patients.

They've managed to work through more of their mother- and commitment-issues. They're finally getting around to planning their household on a mountaintop.

Will they make it past the building-permit stage? Hard to say. Soap operas never leave everyone unequivocally happy. But a show that made its mark by having fun with melodrama - then somehow forgot how to be mellow - seems prepared to get the party music cranking again.

It's not a terrible way to start anew.

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.