You could cut them. Some might work better split on a 45 angle, while others just cut straight across. You may wish to butt the cut edges up tightly against each other, so you minimize the look of too many extra grout lines.

Alternatively, you could use some mosaic tile in that area.

Looks like a lot of people go with a mosaic tile, 1 x 1 sheets. Wonderful.

I also came across a forum where the contractor gets a piece of PVC the same size as the drain hole, and cuts it to the height of the new tile (so the drain cover isn't recessed too far), installs tiles up to the pvc ring, and then grouts as usual. I thought that was ingenious.

A pro tile man can make a shower floor work with 4x4's. You or I would be luck to get 2x2s to look right. That's why the pebble and tiny squares are popular; they are fast and foolproof.
Casey

Having tiled around a shower drain a few times in my life, I would go with the smaller tiles 1x1 or 2x2's. They lend themselves nicely to sloped floors. Also, Home Depot has a nice drain cover that has a whole cut in the center for the drain but is square on the perimeter. Therefore, you have straight cuts on tiles vs the tricky curved cut.
Hope this helps.

Thanks Betty for the suggestion, a square drain cover certainly sounds a lot easier than cutting curves in the tiles (which at this point in time I have yet to learn). I will definitely consider.