however i have not been able to differentiate betweem 720p and 1080p on my 40" bravia. While playing games on my PS3 some games play on 1080 while most do on 720. Till date i cant say which ones which.
NO i idea. But you can see that by playing a much lower res vid in your current set up. The results should be the same.
But since 560p is DVD quality, 720p is HD and 1080p is Full HD you will start noticing the difference only if the screen is big enough to appreciate the changes.
On a laptop its hardy going to matter. The screen is just too small for us to appreciate the difference in quality unless of course you deliberatively look for difference in quality.
As i said i think 1080p holds good till 52" or more maybe.
The future is 4k resolution.