In which other industry do people have as many jobs, or their hand in as many tasks as they do in fashion?

Though Jason Wu’s become a booming success, he’s lending his design skills to Tse next season. His limited edition capsule collection - around fifteen pieces - will debut at New York’s Fall 2010 Fashion Week.

Tse’s been producing Jason’s knitwear for a couple of years, so he already has a solid relationship with the brand and its CEO, Christina Peng-Gerschultz. He told WWD, “I thought, ‘This could be interesting.’ In many ways, I am probably the least expected designer to do this, because Tse’s aesthetic is so different from my own, but that’s one reason I wanted to do it.”

It’ll be sold through Tse outlets, no word yet on the price points, and though it’s being billed as a one time pairing, Peng-Gerschultz already says she’d love to do it again.

A few seasons ago, Julianne Moore “guest designed” a line of cashmere for Lutz + Patmos.

Now the excellent actress is hosting an opening for the rival cashmere house TSE.

The label celebrates its Soho store with a big party on March 11, with Ms. Moore doing the honors (presumably in some expensive neutral-colored knitwear).

Whether this means Julianne is now a face of TSE or whether - like Calvin Klein, Tommy Hilfiger, Hugo Boss, and Miss Sixty - she’s just an enthusiastic participant of fashion (and perhaps a well-paid one), you’ll have to ask her yourself next week.

Or next season, when she’s the inevitable celebrity judge on Project Runway…