Since it's a Sunday, it's likely. But still not as bad as a Fri./Sat. evening. If you try to go earlier rather than later, folks may still be at church.
The last day in 2009 was really crowded/busy, on a Sunday in the afternoon. And there were some drunk groups about. Lines were pretty long. It was my only F&W visit and I figured I didn't need to ever do that again (altho I enjoyed the spendy little snack and wine that I did manage to acquire).
The last day in 2010 was crowded during the day, but not nearly as bad as Fri/Sat. Then it was pretty quiet in the evening. Surprisingly, there weren't as many drunken idiots, either. I had my one-year old, so I was really looking for the drunks.
This doesn't answer your question directly, but this past November we went the last Friday night of the F&W and it was JAM PACKED. By far the busiest we've ever seen the World Showcase. Would never do that again! It was our arrival day at BWI, so we wanted to check it out. Next time if we stay at BWV, we'll head somewhere else that evening.
The F&W is always busy on the weekends. Sundays are usually a bit quieter, but there are still plenty of long lines and crowds. I love going to the F&W, but I prefer to go in October when the weather is a bit warmer and I can spend two the three full days in Epcot after venturing to all the other parks first!