It’s springtime in TV land and the process of sprucing up primetime schedules is well underway as U.S. networks prepare to trot out fall skeds during the upfronts in May. It’s a pivotal time for Canuck programming execs at CTV, Global and Citytv, who will be one-stop shopping in L.A. to boost their primetime offerings and fill the void left by cancelled or retired shows – including long-running favorites 24 and Lost.

Several freshman series, such as breakout hit Glee, have already secured their spot for fall alongside the usual suspects including crime franchise CSI and its spinoffs, and hospital-set hits Grey’s Anatomy and House. But the fortunes of some, referred to as on-the-bubble shows, remain unclear.

Which shows are back? Which have been kiboshed? And which are still facing the chopping block? Here’s how things stood as Playback went to press on April 30.

WELCOME BACK

• Vampire Diaries – The CW/CTV
A second helping of the rookie series starring Canuck Nina Dobrev is in store on The CW, where it became one of the U.S. net’s top-rated shows. The teen romance was also a strong addition to CTV’s Thursday lineup, where it found an audience in the early primetime 7 p.m. slot.

• Cougar Town – ABC/Citytv

• NCIS: Los Angeles – CBS/Global

• Glee – Fox/Global
The freshman hit has been a bright spot in an often crime-heavy primetime lineup for Fox and Global – garnering strong ratings, critical praise and a Golden Globe for best comedy/musical series. Fox quickly renewed Glee for a second season back in January.

• 90210 – The CW/Global

• The Good Wife -CBS/ Global

• Parks and Recreation – NBC/Citytv
The debut season was met with mixed reviews, but the comedy fronted by Saturday Night Live alum Amy Poehler really made its mark the second time around, landing on numerous ‘best of 2009’ critics lists – prompting a third-season order.

• Fringe – Fox/CTV

• The Marriage Ref – NBC/Citytv
Jerry Seinfeld’s relationship reality helped fill one of five gaping holes in NBC and Citytv’s 10 p.m. timeslot left vacant by the abrupt cancellation of The Jay Leno Show in February. Marriage Ref has been picked up for next season, though reviews have been scathing. Programmers might recall the first season of Seinfeld’s original series which, though a hit at the end, stank up the airways its first season, too.

• Parenthood – NBC/Citytv

• Castle – ABC/A/CTV
One of the most popular dramas on ABC, the detective series starring Canucks Nathan Fillion and Stana Katic received a 22-ep third-season order thanks to strong viewership in the competitive Monday 10 p.m. slot. CTV also recently promoted Castle from A to the main network for its last three episodes of the season.

SAY SO LONG

• 24 – Fox/Global
Kiefer Sutherland’s real-time action series is retiring after a marathon eight seasons on Fox and Global, where it was a reliable performer on Monday nights. It won’t be the last we see of special agent Jack Bauer, however, as a feature film based on the series is in the works. The two-hour series finale airs on May 24.

• Ugly Betty – ABC/Citytv

• Lost – ABC/CTV
The pricey cult drama, a big critical and commercial hit in 2004/05, is wrapping after six seasons with the final episode on May 23.

• Trauma – NBC/Citytv

• Dollhouse – Fox/Global
Global is left with a hole in its Friday 9 p.m. timeslot as the sci-fi drama by Joss Whedon was axed after two seasons back in November due to low ratings.

CLOUDED IN UNCERTAINTY

• V – ABC/CTV
The Vancouver-shot sci-fi series has yet to receive a second-season pickup, having struggled to secure a loyal audience on Tuesdays. Part of the problem was its three-month hiatus last fall after V had only aired four episodes. Those special effects don’t come cheap either.

• FlashForward – ABC/A

• Mercy – NBC/Citytv
The freshman medical drama is sinking in the ratings and may prove that NBC has not yet found a suitable replacement for the granddaddy of all hospital sagas ER.

• Human Target – Fox/CTV

• Chuck – NBC/Citytv

• Heroes – NBC/Global
The sci-fi drama arrived with a bang back in 2006 and quickly won favor with critics and viewers, but subsequent seasons have been criticized for slow pace and drab storylines, which could make Heroes’ fourth outing its last.

• Lie to Me – Fox/Global

• Numbers – CBS/Global