Actually, up until very recently, I've still been buying 45's with new music on them. How it works nowadays is:
EPIC label artists have the same song, same mix, both sides, usually no picture sleeve, just a generic EPIC sleeve.
WEA label artists USUALLY have TWO hits on one record, with the B-Side strangely foreshadowing what the group's next big song is going to be. Usually no picture sleeve, generic plain white.
BMG label artists sometimes come with the same song on both sides, sometimes a different mix, sometimes a single-only song. Very Cool.
Actually, that happens with the WEA stuff sometimes, too, as some of my Madonna's 2 or 3 years ago (Don't Tell Me, Music) came with remixes or unreleased B-Sides.
A label called "Collectables" is still releasing stuff, too, mostly oldies, containing 2 hits on one disc, great for jukeboxes and easy on the wallet that way!
Sadly, as the years go by, there are fewer and fewer of these releases. As it stands, each of these is usually in a limited release of about 5000 discs TOTAL, making each purchase a collector's item immediately!!
The last one I bought was "Addicted" by A Simple Plan, and it came in a nice semi-hard cardboard glossy picture sleeve, with TWO songs on the B-side!! Nice indeed!! These just aren't happening too much anymore, though. *sigh*
Well, I'm rambling.
eric