"Romney is the only one with a chance to win against Obama"
I think that's a foolish assumption, especially since I remember people saying back in 08 that the Democrats better nominate Hillary if they wanted anyone with a chance of winning the election. Romney's "strength", in my opinion, is the general feeling of ambivalence most people have towards him. Unlike Gingrich, Paul, Santorum, Perry, etc. there isn't a lot of reason to hate the guy, just as there isn't a whole lot of reason to love him. He's just "okay" in most ways and doesn't do much to make people love or hate him it seems. That's a recipe to get elected if your opponent has a lot of reasons to be hated I suppose, (makes you seem like the lesser of the evils at the very least) but it's not realistic to say that it's the only way to win this election.
"Romney is presidential and good at debates"
From a perception standpoint this may be right. I don't find Romney likable and I really don't think most people that actually pay attention to what he says will either. He is a skilled politician in the sense that he can speak for hours and hit his highlighted talking points without saying anything of real substance or actually answering any questions. Clinton was skilled at this too (more skilled, I'd argue) but being able to speak well or redirect a conversation in your favor isn't the same thing as being likable. I like Paul and Gingrich more from a speaking standpoint simply because they don't bullshit as much and talk in circles. They answer a question and tell you what's on their mind (whether it's the truth or not I have no way of knowing, but that's true of anyone) in a no-nonsense way and that's much more likable to me than the "better" speaker Romney. Romney does have a more presidential look to him for intangible reasons I can't explain, but I don't find anything about him likable. I liked him more when I hadn't listened to him in debates and interviews, but like Obama, his speaking ability is a lot less impressive if you're actually paying any attention to content and I think Romney won't appeal to the more attentive/educated electorate for any other reason than the general ambivalence I mentioned earlier. That's just my theory though, maybe I'm alone on this.
"Romney dominates debates"
I read this, and I agree that he is possibly the most skilled speaker, but what this guy generally fails to point out is that he uses the same techniques that the author claims lets him "dominate debates" to avoid answering most of the questions he is asked. Stephan-however you spell his name-oppolus had to ask him the same question several times in one instance during the New Hampshire debates and still couldn't get a straight answer out of him. I respect a candidate who answers a question with substance much more than one that's skilled at craftily evading it.
"The Republicans don't have anyone else electable to run against Obama"
Well, I think Perry and Santorum are doomed eventually due to lack of substance and polarizing statements, and I haven't liked either of them from the start, but that doesn't mean I'm necessarily right or that they can't somehow pull it off. I really don't think the statement is believable though, simply because the Democrats don't really have a lot in Obama either. The shiny rhetoric and marketing of the 08 campaign has lost all luster simply because it was pretty much a one-time-use tagline and when you get down to substance he doesn't have a whole lot going for him either. I still think his reasons for getting elected (other than a very unfortunate Republican ticket) have nothing to do with his overall personal strengths or platform and that re-election will be much harder for him because of that. Obviously it's still anyone's game at this point, and as such it's shortsighted to rule out the rest of the republican field. Most people weren't expecting a McCain nomination or an electable Obama at this point in 08.