It will lag extremely bad if you set the resolution to 1080p (your TV's native resolution). The GMA 4500 integrated graphics isn't good for gaming at all to be honest. I temporarily had access to a laptop with an Intel 4500 chipset in it, and it was definitely not fun to play with. At the low resolution your laptop's built in monitor has, it might work on some games with lowest settings. But 1080p is equal to 1920x1080 resolution. That's going to tax your laptop pretty heavily.
Setting your graphics resolution to anything less than 1920x1080 on your TV may not result in optimal viewing either. The TV may or may not handle random resolutions very well.
For movies and such, it should be awesome though.