The DVC resorts run at or near capcity pretty much all year. So expect to be in a full or nearly full resort no matter when you go.
Certain times of the year and certain types of accomodations book quickly and are often difficult to impossible to reserve as you get closer to arrival. The smaller resorts do tend to book up more quickly than the larger ones, but that should not be a surprise.
The end of April/first part of May is generally not a time that you need to reserve 7 - 11 months prior to arrival. That said, if you are looking for a GV, a 2 bedroom with 2 queens in the second bedroom at BCV or a SV or BW view at the BWV, you pretty much have to have the home resort booking advantage to be sure of getting what you want. It's not impossible, but it is not probable, either - plan to call day by day at 7 months if you want the best chance for those types of accomdations and have to use the 7 month window.
It's very late to be looking for that time of year now. Availability will be limited and you may have to change resorts during your stay to get all of the days you want.
We joined DVC last February, and all of those new points were just burning a hole in my pocket!!! I called Member Services and was able to get a 2BR villa for six days at our first choice, VWL, with only three months notice! I was really surprised since VWL is one of the smaller DVC resorts. Our stay was in the early part of May 2006.
So, based on my experience, I'd say your chances are great!
A couple of years ago I was able to get a standard view at BWV for late April at the 7 month mark. I also got a 1 bedroom at OKW for early to mid May many times at the 7 month mark. It's a nice time of year to go, not very crowded at the parks.
I just called on the 13th--was able to book 1BR BCV for one of the two nights in early May that I wanted (I wait listed the other night).
I called back on the 14th since I still had banked/borrowed points left --I thought I'd best make a ressie somewhere (anywhere!) for the other night just in case the waitlist didn't work. They had both nights available at BWV, so I switched to BWV!
I too am hoping to get a room. I should be closing this week and then i am assuming 7-10 days to get in the disney system. I have Pop Century booked as a backup plan, but are hoping DVC will come through!
I just spoke with member services and was able to add 1 night in a 1 bdrm at OKW for April 21. She said that there were at least 25 available for that night.
Last week we were able to snag the "very last studio on property" at SSR for the second week of May. We considered ourselves very lucky with our last minute trip.