Tonight's season finale of

Grey's Anatomy

is a big, meaty, two-hour wrap that promises to resolve that Mer/Der thing, and maybe - OK, almost certainly - tell us more about that Hahn/Torres thing, too.

ABC and even the normally loquacious creator Shonda Rhimes, who every year around this time likes to spill to Entertainment Weekly, her own personal house organ, have been circumspect on finale plot details.

Yes, there's the picayune ABC wrap that says Meredith (Ellen Pompeo) and Derek (Patrick Dempsey) will "successfully" complete their clinical trial, though it does drop an alluring tip - that Lexie (Chyler Leigh) will learn something odd about the "intern status" of George (T.R. Knight).

That's it. We're otherwise left to fend for ourselves. (Though, as promos promise, Cement Boy must be freed from that block of hardening concrete; umm, why weren't the firefighters called in?)

Clearly, there's one massive element that will, or must, crowd these two hours: Meredith's incredibly difficult exercise in self-awareness, and the abused Dr. Wyatt (Amy Madigan) who's midwife to her demons.

Griping about

Grey's Anatomy

is almost as popular (and tiresome) as griping about

American Idol

. The truth is, these complaints are richly justified.

But whether gripers care to admit it,

Grey's

has improved in recent weeks. Reason? We see forward - and not circular - movement, for a change.

Grey's

was so damaged by the Izzie/George affair early in the season that if blog threads were cords, then a few million fans would have strangled the show with them.

Izzie (Katherine Heigl) and George and Cristina Yang (Sandra Oh) are solo again, while Erica Hahn (Brooke Smith) and Callie Torres (Sara Ramirez) are about to embark on what Hahn might call a "Sapphic adventure."

And Meredith, for the first time in just about, well, forever, is tackling that which psychically ails her.

Pompeo candidly told EW that "the relationship stuff with Patrick was . . . so repetitious and I had nothing new to give."

We know! Everyone knows, Ellen! (And finally, Shonda does, too!)

Madigan's Dr. Wyatt promises to heal not just Mere - and enrich Mer/Der - but maybe even an entire franchise.