Cavalary: As far as I'm concerned the terms are strictly about the gameplay, regardless of where they were developed... Though I'd be tempted to say that the term JRPG describes a particular style, while WRPG tends to describe an RPG that's not an JRPG.
Septerra Core seems to me as a perfect example of a JRPG developed in the West.
It seems odd to define it that way, with WRPGs being "everything else". One thing is that, as a rule, WRPGs are significantly more complicated than WRPGs.
For example, if you drop an item, typically:
* In a JRPG, the item will just disappear. That's if the game lets you; some JRPGs lack the ability to drop items, instead giving you an infinitely large inventory that never fills up (and there's no encumbrance mechanic, either).
* In a WRPG, the item will remain on the ground, and you can pick it up again later. (How much later depends. Wizardry 8 has items remaining on the ground forever, while in Ultima 6 "transient items" (typically items that don't exist at the start of the game and aren't quest items) will disappear if you leave the area.)
Encumbrance is another thing you find in WRPGs but not JRPGs. Also, WRPGs have fancier dialog interactions.
In fact, you could reasonably say that WRPGs have more of everything than JRPGs. (Watch out, however: this includes bugs! In particular, game-breaking bugs are *much* more common in WRPGs, mainly because the game has to keep track of more stuff, particularly outside of combat (including stuff related to main quest progression), which leads to a bigger surface for bugs. JRPG bugs, on the other hand, usually relate to things like combat or stat growth.)
There are, of course, games that straddle the line; the Romancing SaGa games are my favorite example here, and there's also Unlimited SaGa. (SaGa Frontier 1 and 2, especially 2, are a bit more on the JRPG side.)