Today was both great and sad. Great because I wrote 2970 words, and reached tomorrow's goal, too - 45.000 for me! (I'm going to add in those last 30 words to make it another 3000 day). Sad because it was the last write-in, and NaNo was over so soon. I'm pretty sure I'll be doing Camp NaNo during April, so I can cheer up.
Fen Shen, the last week is not necessarily easier. Week three is what a guy over at the YWP (which I sometimes check for fun) calls the Swamp of Despair, and I personally can say that week 4 is not the Swamp of Despair, but it is not easy either. It's more like "Dang, so little time to write! I have to write more!" At this point I'm trying to fit anything into those 5000 words that I have left. And your novel may very well be complete before the 50k, that's even better! The goal is to have a novel, not a long novel!
Also, may I suggest you to join us over at @NaNoWordSprints on Twitter? I find it incredibly productive for the word count. A couple of hours sprinting give me about 3k a day.