Ad and flash blocking are available as Chrome extensions (with whitelisting/exceptions). The extension ecosystem is just as extensive for Chrome as it is for Firefox; the one exception being bulk downloaders (Chrome, at this point, will open rather than download the media files it can handle, so downloading full-sized image galleries from a thumbnails page won't work properly). There are some extensions that Google can't approve of (YouTube downloaders and so forth—since Google own YouTube and makes money from the ads, it's not likely that they're going to give a downloader pride of place in the Web Store), but you can get them from non-Google sites. Installation isn't automatic—you actually have to drag the downloaded CRX file onto your extensions manager page (oh, the horrors of moving a mouse half an inch!!!).
Chrome (and the open-source Chromium, if the Googly part of the app bugs you) already has a good debugger/inspector/profiler built in, so an add-on like Firebug isn't necessary. I do use the Web Developer Toolbar, but only for its predefined window sizes when developing responsive sites.
And you folks who are worried about the "huge virus vector" that is IE... well, you're just a little bit behind the times. Internet Explorer 9 and 10 are at least as secure as any other browser, IE8 is well-patched, and since IE is no longer the market leader, it isn't nearly the target that, say, Chrome and Firefox are. Opera weirdos will probably never have to worry; it's highly unlikely that it will ever have a big enough market share to be a target. Opera Mini saw wide distribution, but the browser didn't browse; it only looked at pictures of the web page after the server did the rendering. That makes the browser secure (while opening the server to abuse), but it makes highly interactive pages useless.