not really. dpending on the size of the screen it can actually end up being worse.
Just to elaborate, 720p & 1080i tellys have 720 horizontal lines of display. 720p displays each line in order which gives a smoother picture, while 1080i does alternate lines (usually starting with the odd numbers) which can be quicker, and sometimes sharper picture.
1080p does what it says on the tin. 1080 lines of display, displayed line by line. The main downside is that if you are watching standard TV broadcast in 480i (480 lines of detail, interlaced display as per SD) the 1080p has to fill in more gaps
Let me explain further. If you image a standard, 480i tv image containing 20 square pieces, filling the screen nicely, then transfer this to 720p tv which can display 30 squares, then the picture can suffer as the tv has to best guess what to put in the extra 10 squares to complete the picture. This up scaling, while good, is not perfect. Go one step further to 1080p, and all of a sudden you can display 40 squares, causing standard tv images to appear fuzzy. Its not terrible, but it can be noticeable on high speed images like sports.