Well, it depends on Tru does the next few months, especially Episodes 14-20.
It didn't guite get a full season (22+ episodes), so usually that means that the network intends to pull it for May sweeps. That isn't a good sign.
Dark Angel averaged 40% more viewers than Tru and didn't get a 3rd Season.
However, I think that Gail Berman (president of the Fox network) might be swayed by the reasoning that it was up against fearce competition, and if they retool, bring in a new show runner, introduce some new characters, that it could be more competitive.
That isn't the usual Fox pattern. Usually all they look for is immediate hits, which is why there's so many shows that have been canceled. But Fox has so many gaps in their lineup, that perhaps they'll grant an acception to Tru.
However, Fox does have a huge lineup of mid-season shows, and have put quite a few shows in production for late spring/summer, and more pilots that usual. They have plenty of shows to replace Tru Calling with.
Gail Berman was the one at Fox that gave Buffy a chance after less than steller ratings. However, Buffy's first season did have higher ratings than Tru, despite being on the fledgling WB network. If it wasn't for Gail Berman, Buffy might never have gotten off the ground, and from her recent comments, she believes in Eliza. So hopefully she'll go to bat for Tru.
Recently Fox has greenlight 25 episodes of a reality soap opera, that analysts say is a cheap alternative to scripted programming for Thursdays or Fridays. So Fox isn't going away from reality programming. In fact, they're giving this show more episodes than Tru Calling. So I'm not sure that's a good sign. This stupid soap is expected to premiere in April, right around the time Tru Calling's season finale will be on.
My guess is it's 50/50 right now. If there's an improvement in the quality of the show in episodes 14-20, no matter what the ratings, I think it will increase the chances.