I hear that most of Munich is closed this week, is that true? What is there to do this week for tourists?
According to the website of Deutsches Museum, they are open daily 9-5 except: 24. 12. 2010 Weihnachten 25. 12. 2010 Weihnachten 31. 12. 2010 Silvester The Residenz and Schloss Nymphenburg are also closed the 24th, the 25th, and 31st. There is nothing on their website to indicate the Hofbräuhaus will not be open every day. According to the Dachau website, "The Memorial Site is open Tuesday through Sunday, from 9:00 am to 5:00 pm. On Mondays the Memorial Site is closed. " The German language side says the Memorial is closed on Mondays (except holidays). The 27th is a Monday (but not a holiday). Outside of town, Neuschwanstein is closed Dec 24, 25 & 31. It looks like during your time period, only the 31st has closings. But, beware, the 26 is a national holiday. Things might be a little busy.
Most of the major tourist destinations in Europe see a spike in visitors during the holiday break. With the exception of Christmas and New Years day, many restaurants and sites remain open.