Despite gloomy gray skies, Irish eyes are smiling as the 2011 Toronto Film Festival launches tonight with the world preem of Davis Guggenheim’s U2 docu “From the Sky Down” on the Gala screen. It’s the first time a nonfiction pic will have opened the fest, bucking the trend of recent years to open with a Canadian title or Canuck co-prod.

“We wanted to establish a more open policy in terms of the kind of films we look for to open the festival and really kick things off,” commented festival co-director Cameron Bailey. “Last year the Bruce Springsteen documentary was one of the biggest films of the festival, and that same kind of energy propels ‘From the Sky Down.’ The film explores and celebrates the creative process, and we’re all about the same thing.”

Earlier this week, the fest announced that an onstage discuswith Guggenheim, U2’s Bono and the Edge will take place Friday afternoon. And the music docu note is sustained with the world preems of Cameron Crowe’s “Pearl Jam Twenty” and Stephen Kessler’s buzzing “Paul Williams Still Alive” also unspooling this weekend.

The Canuck contingent, spread throughout fest programs, hits a high note Saturday with the world preem of Sarah Polley’s sophomore feature “Take This Waltz” and the North American preem of David Cronenberg’s cerebral drama “A Dangerous Method” on the Gala screen. Other hot domestic titles in play include Randall Cole’s “388 Arletta Avenue,” Guy Maddin’s “Keyhole” and Dylan Akio Smith and Kris Elgstrand’s “Doppelganger Paul.”

As sunnier skies beckon for Friday and the preem and party-packed weekend, record numbers of industryites (up 10% over 2010’s headcount at this juncture, with larger numbers from China, Japan, Korea and Argentina) roll into town expecting greater U.S. buyer heat for the abundance of available titles, especially given the larger competitor field.

“Toronto is like the first day of school” said IFC Films/Sundance Selects exec Arianna Bocco. “It’s the first fall festival with significant new titles, but despite being a screening-heavy festival, it’s an important part of the ongoing conversation with sales agents we haven’t seen since Cannes and a time to catch up because AFM is literally around the corner.”

In addition to festival title action, market activity in Toronto will see discussions ignite for 2013-timed projects, with sales of non-fest titles also in play. For instance, Submarine screens docu “Diana Vreeland: The Eye Has to Travel” early Thursday evening to anxious buyers unable to catch the docu at its well-received Venice and Telluride screenings and expects to close a deal Friday.

This year the fest is fully ensconced in its downtown hub, with action radiating around the five-story TIFF Bell Lightbox at the corner of King and John Streets after a full year of programming to work out logistical kinks.

On Wednesday the Lightbox was abuzz with the launch of the four-day Talent Lab as 24 emerging filmmakers primed for creative development entered sessions led by governors Jason Reitman and Bingham Ray. Wednesday morning, winners of the Emerging Filmmakers Competition (shorts helmed by Canadian 2010 Talent Lab participants) were announced, with Montreal’s Kara Blake nabbing the juried top prize for “Next of Kin,” Gabriel Taraboulsy landing second prize for “My First Movie” and Jared Raab’s “The Revenge Plot” winning for fan favorite.

Friday night the festival anoints a new red-carpet venue with the world preem of Polish helmer Malgoska Szumowska’s “Elles,” starring Juliette Binoche, at the Princess of Wales theater, a 2,000-seater (less 500 to make room for the removable high-tech projection booth) located across from Roy Thomson Hall (Gala central).

“We’re running films there from Friday through to Monday, which is when we have the highest demand for bigger films that can fill that size of house,” said Bailey, adding that the fest hopes to use that venue for more days in future editions depending on the response. “I think ‘Elles’ sets the tone for what we want the Princess of Wales to showcase, which is high-profile films with prominent talent but subject matter more challenging that what we might program as a Gala.”

Travel time for media and buyers is reduced with press and industry screenings split between the Scotiabank theaters and the Lightbox, while official press conferences will be held in the Lightbox’s sixth-floor (elevator access only) Malparte event space. And most U.S., Canadian and foreign PR companies are with the program, setting up shop either at the fest’s official industry hub, the Hyatt Regency (one block from the Lightbox) or at the Intercontinental on Front Street, a stone’s throw from the hub.