Your TV will display 1080i, so you could certainly see an improvement by viewing blu-ray (1080p content) rather than DVD (480p content). Since your TV will not display 1080p, you're not losing anything by using the component video cables.
One of the things I really like about the newer crop of blu-ray players is the ability to stream content from other providers (like Netflix). Likewise, blu-ray offers better audio than regular DVD.
So, yes, I think there is a good chance you'd find some value in a blu-ray player.
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