Just picked up on a killer app, coming from Yahoo’s web mail team. Apparently, Yahoo is now integrating IM into their web mail client. I haven’t been able to give it a go yet since it’s not available to all Yahoo Mail customers, but from the shot that CNET grabbed (seen below) it looks like a really rich experience. Google released a similar feature for GMail last year, but it seems like Yahoo is doing it a little bit smoother.
That said, we’re really interested to see what Microsoft has in store for it’s next generation Web Messenger this summer.