Warbler Guy, is it unusual to see wood-warblers at backyard seed feeders? Wood-warblers at feeders I can expect to see?

Jerry (in southern Michigan).....Great question, as in your area this time of year (November and, indeed, through ~February or so) I'd expect potential seed feeder sightings from a lonely, uncommon Pine Warbler or Yellow-rumped Warbler.

(Above: male Yellow-rumped Warbler, 
Setophaga coronata audboni, 2007, Cupertino, CA (male breeding plumage). Photo courtesy of creativecommons.org....Note: Obviously, winter-time sightings of this species do not typically "wear" breeding plumage like the individual shown above.)

On the West along coastal California (where I live in the SF Bay area), it's not common, but Townsend's Warbler could show up along with Yellow-rumped. 

Yellow-rumped subspecies in the lower 48 states —both Myrtle and Audubon's — are able to digest waxy coatings on seeds (such as privet and wax myrtle berries), unlike most other wood-warbler species....That's because they have hearty digestive juices to process seeds (as does Pine Warbler).

Otherwise, I have to admit in my 40 years of birding, I've never seen any other wood-warbler species at seed feeders.....though backyard nectar feeders sometimes coax Cape May Warbler, among other songbird species.

OK, I'm out to watch raptors today, later, then soon conducting a birding tour soon to Bodega Bay (in Sonoma County, 60 miles northwest of San Francisco) so wishing you the best.....Please feel free to see my "Birding Tours" area at my web site: warblerwatch.com

Regards, Daniel Edelstein