There's no way to answer this without considering level.
Low-level 4e characters are way, *way* too powerful compared to the commoners around them (and that they recently were, it is assumed). They get hero status handed to them at 1st level, rather than having to earn it...doesn't quite fit, somehow.
I don't know about mid-high level 4e characters but given the way the powers etc. seem to scale I'd say they probably get more in line with where they should be (relative to the greater world) as the levels get higher. I don't see them ever being underpowered, though.
Lanefan
I too prefer to have the PCs earn their "hero" status over a few of the lower levels, which is partly why I'm not rushing out to buy 4e product. I do think that the 4e convention of starting characters at a slightly higher level of power appeals to many people who would otherwise not stay interested after playing a game at lower levels due to higher mortality rate. Personally, I like knowing that even the fighter in a level 1 party can die from a single well placed hit. As far as I know, nothing in 4e of appropriate level will kill a PC in one shot.