Oh, you know they're going to redeem Sylar. They've been playing with it for ages. They made a point to give the character layers starting with The Hard Part in season 1 and pursued it big time in season 3 (which I thought was EXCELLENT). They've made him almost more of a tragic character now than a villain. That's not poorly written. That's called character growth. It's not bad writing because you just want a 2-dimensional villain who gets offed immediately.
Does Darth Vader ring a bell?
I totally suspect that Micah's "you could save us all" was there for a reason.
Hmmm... let's just say that there have been examples in the past that prove that a villain being presented as more complex, more sympathetic, tragic or even somewhat heroic at times, is no guarantee that there would be a redemption story.
With TV shows in particular, there are many factors that influence storylines, such as - a bunch of writers with different ideas, disagreements among writers, disagreements between writers and actors, attempts to satisfy different factions of fandom which have completely opposite wishes, outside factors (such as an actor leaving, early cancellation, writers/actors strike, network interference, etc.), and a lack of a long-term planning.
Heroes has suffered from most of those to a ridiculoous degree, with writers being sacked, leaving, coming back and leaving again. You just have to look at how they've been completely ignoring most of the plotlines they introduced in volumes 2 and 3, or the characters who were introduced with a lot of hype, barely used and then killed off either because the character was unpopular, or because the actor was busy, or for some other mysterious reason... Those guys obviously don't care much about continuity, and I would not bet on them developing any plot in any seemingly logical way. They've proven that they can do pretty much anything (short of killing off Claire, Peter, Sylar or Noah for real). This actually leads to one of the show's main charms, the unpredictability of its storylines - although, ironically, this does not seem to be a result of an artistic intent or even a desire to shock, but simply the fact that the writers team don't seem to have an idea what they're doing.
If I didn't see the Ellen interview, I might have worried. But he's so good with Mr. Muggles in their scenes together that I knew he has to be a good guy. And a dog person. 
....but seriously - if he weren't as good at his job would as many of us be watching?
And that Karl Urban guy too - Eomir was it? Thought Haldir vastly underrated - thanks for the tip!
They don't know what to do with Claire anyway...at least squicking us out is a reason for the character to exist.
