Apparently these aggregation services are not catching on. This article reported that Wells Fargo just announced that it'll be shutting down its online aggregation service. Citibank ended its Yodlee account aggregation service last September.
The article mentioned the concern about online security as one reason why account aggregations services are declining in popularity. Yodlee is trying to overcome these security concerns with a partnership with RSA Security. Yodlee's goal is to implement a two-factor authentication system that'll work with its aggregation system.
Security concerns were mentioned a lot on this Fatwallet thread about Yodlee and account aggregation in general. I'm not sure if the extra convenience is worth the risk.