Some would argue that the extra resolution is meaningless for most people's uses... and they'd be right. However, some 720p LCDs accept 1080p signal and downscale the signal, some don't. You may never really need the extra but if your budget fits and the TV is generally considered to be of decent quality in all other regards (the Samsung is) then I reckon you'd be wise to think twice.
Sony make some LCDs that are 720p resolution but accept full HD signals (1080p). They are rather pricey though. Both Samsung and Sony make 1080p tellys that will cover all bases and the Samsung is better priced. Check http://www.zettavolt.co.uk/HDTV/All.html for lots of price and feature comparisms.