Alright! I saw it last night and aside from a few minor things, I really enjoyed it. Didn't check my watch even one time! And that's usually how I measure my interest in a particular movie.
Here goes my attempt at a review.
"Lake House" is actually a remake of a Korean movie. So not all that original in the broad scheme but then, who here watches a lot of Korean movies?
So it works.
The movie is pretty calm and pleasantly paced the whole way through. It starts off nice, you see the man and the woman doing their thing, each in their invidiual lives.
We know they are two years apart, but in the movie you don't know who's where for a little while and as the movie continues, it becomes increasing hard to tell whose reality you are watching, which is what is GOOD about the movie.
The complicated thing about future/time travel-ish stuff is the whole problem "Do bad things happen when I mess with things or when I don't?"
There are some twists and clever things that had me quessing. I was watching with Anne and Evangeline, Evangeline had seen it before. So I was guessing and trying to get her to confirm things.
Also, I usually don't notice the background music and such, but at certain climatic parts, I really enjoyed the music.
There were also some neat camera shots and such.
LA END!
SPOILER:
HAPPY ENDING!
Four out of the five of us enjoyed it (all girls) so that seems like a decent approval rating! It was so sweet sometimes, and even though I knew about the 2 years thing, it was still interesting to see how it fit together and trying to figure stuff out. It was definitely cleaner than a lot of romance stuff out of it, though I couldn't give it a total clean rating. It was still quite good, at least in my opinion, and I definitely want to see it again to try and notice things that I missed the first time! 
