I haven't had any accidental catches this year like some springs, but based on the weather pattern I'd say most are done spawning and have been for awhile at least in southern and central WI, though with the cool down, they are probably still going through the motions, though their egg masses are probably empty.
With that said, there are always a few late comers to the party, fish that stayed deep till now and are finally showing up to spawn. Thats a relatively low number. What many don't realize is that Muskies don't need the actual channel or main lake surface temps to be in the 50's to spawn. Once the first north bay hits the high 40's they are already there. Often times, and it occured this year no doubt with the hot weather a few weeks ago, Muskies will be spawning in backwater shallow/quick to warm bays while Walleyes are spawning up the river or on main lake shoals.
[This post was last edited on 4/28/12 at 6:23 PM]