Apple has, with little fanfare, added a 3.33GHz Core i7 Xeon 3500 (Bloomfield) option to its Mac Pro lineup for quad-core/single-chip models. Comments by the usual suspects in Cupertino have mirrored community speculation that this is a (weak) response to the new quad-core iMac clearly crushing the value equation of the Pro….but due to its dependence on costly Xeon-class chips, that equation has not changed.

Until Apple is willing to offer a so-called “xMac” model — a headless Pro-class computer with desktop-class Core i7 2G (Lynnfield, as in the high end iMac) chips instead of the far more costly Xeons — the Mac Pro will always be hobbled in competition for the budget-minded power user.

Such prototypes have been spotted in the past, but a variety of factors….notably Apple’s close-knit relationship with Intel which typically dictates which chips it uses even if they aren’t necessarily the absolute best choices for a given market segment….have stood in the way of actual production machines of this type.

Could such a mid-range minitower Mac finally see the light of day in 2010? Stay tuned for some very interesting dirt on this topic when source embargoes expire in the coming days….