Fascinating thread, just a couple of things to add. For our friends across the Atlantic, what you refer to as "warm beers" are the equivalent of the hand-crafted beers you get from the current crop of microbreweries over there. They are called "Real Ales" over here. It is mostly an English phenomenon (although you do see it to some extent in Wales, Northern Ireland and Scotland, probably decreasing in that order). There is even a campaign but I think you need to have a huge beard to join .

The only beer I know of that is intentionally served at room temperature rather than cellar temperature is rare to find these days. If you find a real "old man's pub" in Dublin you can still find served what is called a "soft pint" (ie served at room temperature) of Guinness. You will only find it in certain traditional pubs, none very far away from the Guinness brewery and the Guinness has to be perfect for it to taste good (but when the conditions are right, it is sublime!). Guinness has never travelled well and even in my home town of Athlone, less than 100 miles from Dublin, the Guinness has been disturbed enough by it's journey that a soft pint is not served...

Unfortunately most people these days want to drink hard and fast, and flavour just seems to get in the way, hence the popularity of the flavourless chill-filtered Buds, Fosters ,Tennants etc. And whiskey that goes with coke. Ah well . Still, I now have a pub in Belgium on my to-do list .