So it seems the latest version of Inkscape is not very psfrag-friendly: If you insert text tags into your EPS then upon saving (even if you deselect "Convert text to paths") it still encodes the tags as things like <01>Tj, which can be worked around by manually replacing each by something like (mytag)Tj in the EPS source, but cumbersome if one has lots of EPS files to tag.
Is there another way people are doing their tagging now? perhaps another vector graphics program, or another way to insert text into EPS all together?
pdfandps/epsexport and is reported as a bug here. Note comment #90 from two days ago (2012-03-26): “Now that cairo 1.12 has now been released, psfrag compatible postscript output is available with a stable version of cairo.” – cgnieder Mar 28 '12 at 16:13