I stayed at three hotels this summer. a quite expensive NH Hotel in Berlin: Extremely expensive WIFI, the Hotel Jurine in Berlin: Free Wifi in their Business section (next building, but it worked from my bed too), The hotel tri Prstrko in Prague - rather expensive hotel (for Prague): Free and good wifi.
I heard about that SAS Radisson have gone from paid to free Wifi for guests: Brilliant, I will do my business travel there next time I have a chance. Just the nuissance to get out your credit card after you got to bed and want to check your mail and chat with your beloved at home is a disaster for a place that claims to care for you.
With regards to login: if it is done well, it is okay, but if you have to login every single time you open your computer, it will be a pain. (oh yes, I forgot the Hotel Koldingfjord in Denmark, best rooms for a long time and free wifi, although with a pretty decent login-system) a very good place for conferences IMHO.