Not sure about "penalization" but yes Google has started considering site loading speed as ranking factor and doesn't like slow sites.
http://googlewebmastercentral.blogspot.com/2010/04/using-site-speed-in-web-search-ranking.html Doggy didn't get its food yet?
yes Google does not appreciate slow loading pages with huge amounts of video, graphics, and the like. this is because the fancy stuff that takes minutes to load isn't going to help people out as much as a less flashy site with equivalent information that loads in only a few seconds or less.
Yes for Sure, as mentioned before it's a factor in Google's algorithm. And Alexa warns about it under 'Average Load Time' of a site. "Note: Slow sites may be penalized by search engines." - Alexa.