To be honest, I can't recall as I never used any EPS files with it.
But there must be a good explanation in the help files i suppose. By the way: they gave the PS5LE classroom in a book for free on their pacific site. I did find the link on the adobe forum. Unfortunately, I just lost all ,my links...
In the manual's index EPS is mentionned, perhaps you can find more info there, or in the help files...
Normally, Photoshop will have to render or rasterize vector information, and this is often very tricky. Still, it is a very useful technique as postscript is the main cause of printer's depressions. Therefore they choose more and more for PDF.