Not a solution, just ome thoughts:
I don't think that it is necessarily wrong that the version being edited is the currently published page. If you select edit in the context menu while viewing I think you'd be surprised if you got an unpublished version (that might significantly differ from the one you just viewed). I agree that that's not necessarily the same situation, but at least consider the other possibilities for reaching the edit view of the page besides the Edit tab (right clicking in the tree, from view mode, are there others?).
That said, the Version tab will display a number to indicate if there are any unpublished versions. I think that counts old versions aswell, but in any case there is already something bringing to the editors attention that there are unpublished versions. Perhaps you can just make this more noticable by changing the appearence of that tab (see for an idea of how to jack into it http://world.episerver.com/Templates/Forum/Pages/Thread.aspx?id=42515&epslanguage=en ). That tab apparently knows that there are other versions, so perhaps ou can use this information (by jacking in to an override of the control) to display an alert somewhere else, a popup dialog or whatever. You can give the editor the choice to go to the most recent version.
Or you could take a closer reflector look at how the framework goes about displaying the "this page is a link to another page" message that appears if you have set the page to be a shortcut.
Thanks, Magnus. I actually wrote a quick-and-dirty plugin to add a "Edit Latest" tab to the left of "Edit" when the version you're viewing is not the latest version. It's pretty obvious, and it leaves the "Edit" tab intact, in case they want to actually edit the current version.
Assume it holds up, I'll blog it later.
Scenario:
There are six versions of my page. Version #4 is published, so there are two unpublished versions ahead of that.
I bring up my page in Edit Mode. By default, this is version #4 -- the most recently-published version. If I press "Edit," I'm editing Version #4, despite the fact that there are two newer versions of this page.
In practice, 95% of the time, someone really wants to edit the lastest version. They want to edit the "leading edge" of the edited content, probably to add onto changes they made previously.
My question is, how hard would it be to modify the behavior of the Edit tab to acccont for this?
My thought is that pressing the "Edit" tab would check to see if the version they're editing is the leading edge -- the most recently version. If not, it would throw up an interstitial page that would say something like, "There are 2 unpublished versions of this page with more recent changes. Are you sure you don't want to edit one of those instead?" The user could then select the current version, or any of the newer versions to edit. I would default the selection to the latest version.
I know you can modify the default tabs, but I think it's more than that -- I'd need to change the postback behavior of that "Edit" tab. How possible would this be?