Both panels are 30" but the monitor would definitely have 16:10 aspect ratio and the TV would have a 16:9 aspect ratio. So the monitor gives you more pixels.
Apart from the ratio the pixel density of the monitor is almost double that of a TV, at 2560x1600 rather than 1920x1080. So if you think blu-ray is good quality, a 30" monitor almost doubles that.
Panel type is also different. TVs are usually PVA panels which are very good but most monitors like the LG and Dell 30" use a S-IPS panel technology. You get more color accuracy, gammut, and viewing angle.