I currently have a site that was recently restructured, causing much of its content to be reposted, creating new URL's for each page.

To avoid duplicates, all of the existing pages were added to the robots file.

That said, it has now been over a week - I know Google has recrawled the site - and when I search for term X, it is stil the old page that is ranking, with the new one nowhere to be seen. I'm assuming it's a cached version, but why are so many of the old pages still appearing in the index?

Furthermore, all "tags" pages (it's a Q&A site, like this one) were also added to the robots a few months ago, yet I think they are all still appearing in the index.

Anyone got any ideas about why this is happening, and how I can get my new pages indexed?