Think about it from the end-user's point of view - if the domain is sold and used for business, then someone will be trying to give out the email address over the phone to customers/clients/etc. Hyphens make that extremely difficult.
OTOH, if all you plan to do is park it - then most parking relys on type-in traffic and nobody types in the hyphen.
So, the only time I would use a hyphen is 1) when I have a known end-user, 2) they definately want a web site for their own business, 3) they have no plans for a big web presence and 4) they simply cannot get an acceptable name any other way. (And then get all the mis-placed hyphen typos and park them on top of the target.)
Just my 2 cents (as someone who owns 4 hyphenated domains).