Hi All
Musical Theatre's my business, so it's really interesting to hear these opinions (I'm usually more of a lurker here, but felt obliged to pop up on this one!)
I agree with you miserableoldgit. Her voice is pretty good -- she's certainly not bad at all -- but there are plenty of stronger singers working in the industry, so some of the hyperbole that creeps into these things is a bit silly IMO. I've worked on Les Mis myself in the past, and most Fantines (not Cosettes, Draganov) are considerably stronger -- but then you'd expect that, they're professional and do 8 shows a week, which really strengthens the voice up.
In addition to the names you mention -- some of whom are on the decline a bit now sadly -- I'd flag up names like Kerry Ellis, Tony Vincent, Sharon D Clarke, Zubin Varla and Jodie Jacobs, who are really, really good (whether or not you actually like musical theatre).
Having said all that, I wish Susan Boyle well. Her passion for what she does seems to come from the right place, and totally genuine, which is nice to see in a genre (as in reality tv) that's usually concerned with the pursuit of fame as an end in itself. She's also clearly got a lot of natural talent. With a bit of training, she'd probably have been a pretty good character actress -- there's certainly nothing wrong with the timbre of her voice. There's still time of course.