I am facing the same problem on my galaxy s2. I am seeing "obtaining ip address" forever on my company wifi network. As suggested by many, I set my phone to connect using static ip address. I have checked my laptop setting and modified the static ip address slightly diff on my phone and copied the other values. Immediately, wifi is connected BUT I am still not able to browse internet, there is no connection at all although it shows that it is now connected.
As the wifi router admin page is protected, I am in no option to change the router setting. How else can I get my Galaxy S2 to work? it doesnt seems like a router issue, but rather a phone problem instead. :(