>1000 seems excessive

Flushing again before 1 second has elapsed won't change any dates, as they are second-granularity. 

>is the `(` necessary?

[Coffeescript won't compile without it](http://coffeescript.org/#try:foo%20%3D%0A%20bar%3A%20debounce%20100%2C%20-%3E%0A%20%20baz%0A). You guys should totally switch to coco, it's superior.