These Sheets Without Die Cuts...

These sheets without die cuts are going to be imperf stamps, correct?

The owner of my local stamp store claimed that sheets without die cuts are still perforated. It's the backing paper that is not cut.

Correct. I do not have first-hand experience (as I have no intention of collecting press sheets) but communication on other stamp related websites suggest that the stamps are in-fact shipped with no die cuts on the face of the stamp.

The real issue is how best to collect them if one desires to cut them apart into blocks, pairs, gutter blocks, etc., as no one is quite certain how they will be listed in the Scott catalog.

I ordered a sheet of the baseball players. My intent was to simply collect the imperf se-tenant, and sell off/give away the others. But I am with you. I am not touching the sheet until I see how the Scott catalog lists it. I'm sure the whole sheet will be listed, but if Scott lists a se-tenant, it's slice and dice time.