On the Netflix blog there's an excellent explanation of what they're doing for encoding and delivery of streaming video entitled "Encoding for streaming
". In that article, under the heading "Delivered Quality", it explains that they use a four bar system of for measured connection bandwidth, for which they deliver 500, 1000, 1600 and 2200 Kbps encodings; for some content, where the source quality is particularly high, they additionally have 3400 kbps encodings which will be delivered if your line speed is high enough. The article also explains that to get a particular encoding, they have to measure a 40% higher connection speed, implying:
(Bit rates are in Kbps).
So your 2 Mbps line speed should get you (at best) the two bar, 1 Mbps encoding. Remember, depending upon the number of hops through the network between you and the server, the real rate for any connection may be lower than the theoretical maximum for your network service. Your distance to the nearest server for Hulu might be less than to Netflix. How many bars is it reporting?
It is what it is. If it's not good enough, wait until you have higher speed service to use it and be content with Hulu.