Matt Dallas in "Bringing Down the House," the series finale of Kyle XY.
© ABC FAMILY/EIKE SCHROTER
Although the immediate threat posed by Latnok was resolved, Kyle (Matt Dallas) is unable to accomplish what Nicole (Marguerite MacIntyre) so earnestly entreats him to do, which is end the intrusion of these people into the Tragers' life.
In fact almost every plot threat opened up in season 3 was left unresolved in "Bringing Down the House," the final episode.
Nate (Jesse Hutch) is still a threat who knows Kyle is the son of Adam Baylin. Mark (Josh Zuckerman) agrees to help Kyle fend off security guards at the Latnok warehouse, and then that's the last we hear of him.
The love triangle between Kyle, Amanda (Kirsten Prout), and Jessi (Jaimie Alexander) is desperately unresolved, except we now know that Kyle feels one kind of tingling with Amanda and another kind with Jessi. (Writer Julie Plec essentially admitted that they didn't know who they wanted Kyle to be with and if the series had continued he would have ended up with neither.)
The most interesting idea brought up in this episode is Kyle's loss of innocence, his willingness to engage in violence and deception in order to defeat Latnok. Nicole rightly mourns the loss of the honest and open Kyle she helped create, but the time to bring something like this up isn't in the last half hour of the series finale.
And then there's – that ending. After a very rushed exposition of who the woman is behind Latnok's manipulations we find out something about Cassidy (Hal Ozsan) that we (a) did not want to know, and (b) have a great deal of trouble actually believing. Plec said that this revelation was the planned story arc for season 4, and when the show was canceled it was shoe-horned into the season finale. So the viewer is left with this piece of information, but is now barred from seeing Kyle react to it or deal with it in any way. It's as if the Star Wars franchise had abruptly ended halfway through The Empire Strikes Back.
So far there are no plans for a Kyle XY movie to resolve some or all of these loose ends, though ABC Family shows lots of made-for-cable movies and a Kyle one-off would be easy enough to do (if they can make Au Pair 3, why not Kyle XY: The Movie?). The cast and crew, however, are already moving on – Plec herself cowrote the pilot for Vampire Diaries, Magda Apanowich (Andi) has been working on Caprica, Matt Dallas is working on the movie As Good As Dead with Cary Elwes, and so on.
Meanwhile there are a number of fan efforts to pressure ABC Family to bring the show back – I've certainly received more mail about its cancellation than anything since the death of Moonlight. Activist sites include Save the Tub! and the Campaign to Save Kyle XY.