On the release of Patch 1.0.4 DiabloNut was updated to show the current version of all skills and items. However, you can also see links to previous versions next to each item if you’re interested to see the changes made to them over time.
But new today is a complete set of pages Dorjan has added which compare the newly buffed and pumped legendaries to their more feeble predecessors, pre-1.0.4. There is a page for each category of item so you can just scroll down through them rather than looking at each item page separately. You can get all the legendaries here.
Although you can get to them from that link I’ve listed each page below for ease.
If there is other stuff you want to see at DiabloNut feel free to pipe in the comments.