Gooie dag, Aravitz!
There is some confusion going on there...
First, there is EPS and EPS... most EPS that you find in the clip art collections are indeed vector files...
But the EPS's that Photoshop produces are raster, encapsulated into Postscript... (that's what EPS means) IF the contents is raster, it won't be automatically rasterized.
Usually, the print companies embed the Tiffs and EPS in Quark, and they prefer these formats because you can insert a Clipping Path in the file. It is, in other words, a Vector Mask.
So, once again, the EPS you can make in Photoshop are not vector ones, if the content is not a vector...
I wrote a tutorial in the current issue of Computer Arts (83) about techniques to vectorize pictures in Photoshop...
The result won't obviously have the subtle gradations that raster drawings have, but it can transform a Photo, or even logos into vectors (Even when saved as Photoshop EPS, if you check the "include vector data") The next time you will open that file, it will ask you the resolution.
To summarize, the key would be for you to recreate the designs as vectors in Photoshop, don't forget to check out the "Include Vector Data", and you've got a file that will need to be rastertized at the next opening.
The PDF produced by Photoshop will keep the vectors (not only the text, Mark 
)but do "remember" the resolution they were created at. (So the rasterizing is not the indication that a file containts vector data.)
