This year card slots seem to be more the standard, rather than the exception.
Keep in mind that having a card slot in its own right, does not necessarily determine what you can do. Last year's V10 Plus, for example has a built in media player so that it can show images and videos on a card (or loaded onto its internal memory). This year, as noted, even the low cost P1 Jr, from AAXA has a card slot, and a media player (a pretty capable one too.)
A media player makes sense.
The combination of a card slot (or lots of memory) and a media player solution is that you can use the projector without having to lug the source with you (DVD player, computer, camcorder, etc). Certainly the ability to leave a laptop behind is tempting for presentations.