"Predictable" is probably being too generous. "Derivative" is the word that best described the premier I saw.
Here's what we've got: a priestess fleeing from the evil troopers of a powerful and dark sorcerer (named, aptly, "Darken Rahl") in a desperate bid to contact some wise old good-hearted wizard who's been hiding out for the last two decades pretending to be a crazy old hermit. The wizard's motive for doing so? To watch over a special young man with a very important destiny--the destinty of becoming The Seeker. Although the lad's training is minimal, he's got heaps of natural talent and still manages to overcome Darken's legions and generally superior resources. Any of this sound familiar? Try swapping out a few words, like "priestess" with "princess".
Mind you, the big problem with the show isn't that it's highly derivative. Derivative is fine if you're dealing with a young audience, because they lack the benefit of having seen the same old crap a thousand times, and they seem to love that "Chosen One" chestnut that's almost offensive to some older folks. No, Seeker's big problem is that it lacks focus on who it's trying to appeal to. Kids won't find much of interest in any of those three characters, and the tone of the show favors grimness and bombast over color and energy. The show doesn't have any comic relief (except for the old wizard's occasional wisecrack), and humor is what makes a work of fiction into something you can relate to even when the setting is fantastic.
BBC"s Merlin is not perfect by any stretch, but it is a much better example of how to make a fantasy show with a Chosen One theme that youngsters can relate to.
Now if the show wants to appeal to adults, then they have a lot of work ahead of them. They've got to make the trite Chosen One angle seem somehow fresh and innovative. They've got to lose the corny villain. "Darken Rahl"? Sheesh. They'd also need to punch up the dialogue, and they still need more humor, just a different type. Oddly, Raimi and Tapert have never hurt for levity in their shows before.