I Too Would Love To See This Feature (for Smartlists and View Schemes anyway).
I'm not sure why the regular old Playlist Export feature doesn't work for your regular playlists. If you switch the Export Format to M3U it just exports the file list (full path) with no other tag info (M3U files are just plain text files that list the path to MP3s one per line).
As far as some proposed future exporting of Smartlists. This would be nice, but it would be important to me to also allow you to export View Schemes in a similar manner. I don't actually use "real" smartlists very often. Instead I use regular View Schemes with a search entered in the "Edit View Scheme" dialog. This lets you have all the benefits of Smartlists, and the benefits of View Schemes as well (including tree population and whatnot). I typically only use actual Smartlists for quick-built lists, or short (time or track limited) lists.
Oh, and an easy way to copy over all the smartlists? Just copy over the Library! You can easily remove all the files and re-import them from their proper locations on the second PC. Of course, if you have data in your current library that you want to save this won't work. If you want to give it a try, I have also had success simply copying the (with MC10, I never tried it with MC11) "playlistx.jmd" and possibly "curplaylist.jmd" (I'm not sure if you need this one or not, I can't remember) files over from one library to another. If you go this route, you can keep all your library data, but copy over just the playlists and smartlists. Of course, this removes all the playlists and smartlists that pre-exist on the destination machine (if any), so it wouldn't work to "merge" the two sets of playlists.
Again, I did this with MC10, but never tried it with MC11. Also make sure you back up your library before you try it (I just copy the entire library folder over to another location on the hard drive.