The old layout is gone, at least to the best of my knowledge. All the functionality is there though. Back button\Forward button is still there. Back List is there in the little icon next to forward. Go Up A Level has been integrated into the address bar. Clicking any of the previous folder names takes you instantly to that folder. Search is integrated to the left of the address bar. Folders sidebar can work as it used to if you open Folder Options (Press ALT with explorer open, go to Tools and Folder options. Or just type Folder Options into the search box on the start menu.) Just click the two checkboxes under Navigation Pane. Changing views etc. is on the context senstive bar to the far right. Delete etc. can be done by selecting a file or folder and clicking Organize on the context sensitive bar. It's all there (and then some).
It's gone since Vista. The new one is better. You'll have to learn how to master them, after that you'll hate the XP layout.