Season three of “The Apprentice” (8 p.m., NBC) will wrap up with a one-hour live boardroom showdown between finalists Tana Goertz and Kendra Todd. For the life of me, I can’t remember who won season two. I do recall that last season’s finale was a brutal endurance test, a half-hour of suspense padded out to what seemed like six hours. At some point Regis Philbin showed up, and then I fell asleep.

So NBC is wise to limit this season-ender to one hour. I do remember Bill Rancic won the first “Apprentice.” He’ll be back tonight and will participate in the boardroom next season.

Next September, NBC will air two different versions of “The Apprentice.” Donald Trump will host the fourth season of his show on Thursday nights. In addition, Martha Stewart will get an “Apprentice” spin-off on Wednesday nights.

It remains to be seen if viewers will warm to Stewart in the boardroom. But more important: is NBC simply over-exposing “The Apprentice”? The first season of the business reality show was a bona fide hit. It revived Trump’s icon status; coined its own stock phrase, yada, yada, yada.

But ratings and buzz have been slipping ever since. In cloning and frequently airing “The Apprentice,” NBC appears to be following the failed strategy of ABC back when they over-scheduled “Who Wants to Be A Millionaire.” That was a hit, too. But then people got tired of seeing Regis Philbin every hour on the hour, and they fell asleep.

• Next season will be the last for “Will & Grace” (7 p.m., NBC). The comedy ends this, its eighth season with a one-hour episode containing three celebrity guest stars.

Eric Stoltz appears as a romantic blast from Grace’s past. Alec Baldwin turns in a creepy, funny turn as a stranger Will meets in the park. He appears to be a fan of Will’s writing, but turns out to be a shady businessman with a very ulterior motive. Seth Green (“Robot Chicken”) portrays an angry child star cast to host the talk show Jack is producing on Out TV.

Tonight’s other highlights

• Sandy feels his marriage slipping away on “The O.C.” (7 p.m., Fox).
• NBA Conference Semifinals (7:15 p.m., ABC).
• Two solid hours of “Blue Collar TV” (7 p.m., WB).
• A flood cripples the ER during Carter’s going-away party on “ER” (9 p.m., NBC, TV-14).