Hmm, did you have an intended mood when you composed this? On one hand the deary weather is mildly dismal and there is a distinct (and I presume intentional) lack of color other than the tree's leaves. However, the focus on the rain and windowpane itself seems like an almost comical reference to other work depicting stoic trees in the center of the image, but you've instead focused on something completely different, making the tree seem unimportant. That's actually a pretty funny effect, highlight a portion of the image with color, but leave it out of focus so it conversely isn't the subject of the work.
Perhaps I'm reading too much into this, nice work <img src="e.deviantart.net/emoticons/s/s…" width="15" height="15" alt="" title=" (Smile)"/>