The Big Ten is definitely in a down year, but I actually think it's not as bad as everyone says. I've been living in the Big Ten for over 4 years now, and I follow Big Ten football--it's a fun and competative league. I don't know why everyone hates the Big Ten so much on this board--there's a lot of tradition and passion in Big Ten football--a lot more passionate than what I've seen from the Pac 10. Michigan, Ohio State, Penn State, Iowa, Wisconsin, and Purdue are football schools and have no problem packing their 65,000-105,000 seat stadiums every week. Michigan State, Illinois, and Indiana are basketball schools, but draw decently in football. Minnesota is a hockey school that will draw a lot better when it joins its Big Ten brethren in building on on-campus stadium (the Dome sucks). And Northwestern--well--they're the brains of the conference.
Anyway, I'd say this year, the Big Ten is better than the ACC and Big East, and competitive with the Pac 10 (which I think is overrated this year). The SEC and Big XII are the top 2 in that order. None of this is saying much because the bottom 4 BCS leagues have all been unimpressive this year. If the Big Ten is an average BCS league, going about .500 in the bowls wouldn't be unexpected.
Conference strength is all cyclical. From 2002 through 2005, the Big Ten was probably competative with the SEC. Let's not forget, as good as everyone says the SEC is, the Big Ten has won the last three Capital One Bowls, which pits Big Ten #2 versus SEC #2. Iowa beat LSU, and Wisconsin beat Auburn and Arkansas. The Outback Bowl, which is Big Ten #3 versus SEC #3/4 has basically been decided by a touchdown or less the past six games (except for Iowa's blowout of Florida in 2003).