What is the scope of the prior conviction exception post-Shepard?

In this post pondering the state of sentencing following the Supreme Court's work in Shepard (summary here), I wondered whether state supreme courts considering Blakely cases will start to get Shepard-focused supplemental briefs.  This question was answered quickly, as today I received from attorney Steve Sanders — who has been involved in New Jersey's Blakely cases as an amicus for the Association of Criminal Defense Lawyers of New Jersey — a copy of a letter brief filled today in the Supreme Court of New Jersey highlighting the significance of Shepard in a pending case.

This New Jersey Shepard letter brief can be downloaded below, and it emphasizes the oblique statement from Justice Souter's opinion in Shepard concerning the scope of the Almendarez-Torres "prior conviction exception."  Recall this passage from Shepard (previously discussed here):

While the disputed fact [in Shepard's case] can be described as a fact about a prior conviction, it is too far removed from the conclusive significance of a prior judicial record, and too much like the findings subject to Jones and Apprendi, to say that Almendarez-Torres clearly authorizes a judge to resolve the dispute.

I have been struggling with exactly what this means for lower courts now considering the scope of the Almendarez-Torres prior conviction exception.  I think Shepard stands for the proposition that the exception is relatively narrow (i.e., the exception does not extend to facts "too far removed from the conclusive significance of a prior judicial record").  And yet, I also read this passage to imply that the Almendarez-Torres prior coviction exception may cover more than just the bare fact of a prior conviction (i.e., the exception perhaps does extend to facts which are very close to "the conclusive significance of a prior judicial record"). 

I believe a number of states have sentence enhancers that turn on whether an offender was on parole at the time of his offense or on whether the defendant previously served a prison term.  Are such facts close enough to "the conclusive significance of a prior judicial record" to fall within the Almendarez-Torres prior conviction exception or are they "too far removed" and "too much like the findings subject to Jones and Apprendi"?  I guess only future Supreme Court decisions will tell.

Download nj_shepard_letter_brief.pdf