Publishing results that were trimmed from another paper I submitted a paper for publication. The editor accepted it but asked that I remove some results to make the paper shorter. He suggested that I put the full paper with the full results in arXiv, and refer to it from the published paper. 
My question: if I do this, can I later send the trimmed results to a different (lower level) journal? I.e, are they considered "published" since they appear in a preprint that is referred from a published article, or "unpublished" since they do not appear in the published article itself?

EDIT: in my field, in general, it is allowed to upload preprints and then submit them for journal publication, so the preprint itself is not an issue; the issue is that the preprint is referred to from a published paper, so it might be considered an "appendix" of that paper.
I suppose you could.  When submitting the paper with the "leftover" results, you'll probably want to explain in your cover letter what's going on, so that the editor doesn't think you're double-publishing those results.

However, I don't think it's a very good idea.  People usually expect a one-to-one correspondence between preprints and published papers.  Having results from a single preprint going in two separate papers will confuse people and make it harder for them to find and properly cite your work.  So if you are going to have two papers, I think you should have two preprints.

So first, decide how you are going to split up the results among papers.  Update the preprint of your current paper so that it matches the content (and title) that will be in its published version.  Then submit a new preprint with a new title containing the leftover results, corresponding to your second paper.

In your current paper, you can then cite the second preprint.