I don't think they're good for branding, promotional work, advertising or anywhere that the domain itself matters as far as type in traffic is concerned (as in people actually typing in your url (incl hyphen)
They are good for seo because the hyphen (at present) is ignored so if you can't reg a decent name in any other extension - but you can with a-hyphen in it, the search engines treat them the same as the premium name without a hyphen..
So if the traffic is sourced via links - use a hyphen because the domain name itself isn't that important.
If the traffic is via google / searches in general (via use of keywords) etc.. use a hyphen because (at present) the hyphen doesn't work against you.
So the answer is yes & no... it depends on a) whether search engine treatment of hyphens will change (personally I can't see why there is any justification for a change)
& b) what the domain is for... direct advertising (off-line) I wouldn't advise it. But links & seo; yes, you can get some good names using a hyphen that you wouldn't get without.
Do I have any hyphenated domain names myself?
A: Less than 1/10th of 1% of my portfolio or in otherwords less than 1 in a 1,000 so you can see I'm not a big fan of them
