jQuery objects visualisation (in console and inspector) are in the Developer Tools, rest is not (though the injection is a bookmarklet/browser extension away)
Well for cookies chrome only shows the value, gives less control than firecookie. Other extensions seems 'hacky' solutions, doesn't feel integrated, some time slow. Also for css editing like add style, increasing/decreasing css rule value firebug is still better than chrome inspector (chrome still does not support increasing/decreasing in metrics tab). But javascript debugging experience is better in chrome. Chrome has good profiler, can add XHR breakpoint, listen for various event listener.
On an unrelated note I can't live without tree style tabs(On average I have 30+ open tabs, which is unmanageable in chrome, hangs some time) and vimperator. All in all I still prefer firefox.
I don't think they're necessarily superior, but I use chrome for everything anyway because it's my main browser. I don't do too much front end stuff, but for JS debugging and the odd css/html hack, it's more than enough to keep me from having to have two browsers open.
I don't use Chrome at all, and don't even have it installed on most of my OS installs. I have Firefox everywhere though, and I'm pretty happy with IE and Safari respectively as backup browsers.
Firecookie http://www.softwareishard.com/blog/firecookie/
Firequery http://firequery.binaryage.com/
Firepicker http://thedarkone.github.com/firepicker/
Jsonview http://jsonview.com/
Colorzilla http://www.colorzilla.com/firefox/