When Apple had a tiny market share, it was prohibitively expensive for them to create too many lines. They had to stay lean and mean.
Now that they are gaining shares and just sold 2.2 million Macs in the most recent quarter, I expect that they will come out with a mid-level headless Mac. In fact, I wouldn't be surprised to see one introduced at MacWorld.
I just hope it has dual-link DVI.
I tend to agree.
When Apple was using PowerPCs, the choices were limited: G4 Desktop, G4 Mobile, and G5 Desktop.
When Apple switched to Intel, the processor choice widened. Intel's processor portfolio is more diverse and allows Apple to do the following:
1. Single Core 2 Duo or Low Voltage Core CPUs for Mac Mini at the low-end.
2. Single Core 2 Duo Mobile for MacBook and MacBook Pro.
3. Single Core 2 Duo Mobile or Core 2 Duo Desktop for iMac (although only the former is used today).
4. Single Core 2 Quad Desktop for Mid-Tower.
5. Dual Xeon Quad Core processors across the entire Mac Pro line.
6. Dual Xeon Quad Core processros across the entire Xserve line (rack mount).
One can argue that historically there was no mid-tower because there was no processor suitable for that segment that would still allow the high-end to remain clearly differentiated.
Today, a mid-tower line could be built with single-socket quad-core processors while the Mac Pro line remains at workstation class dual Xeons, but moves enitrely to 8 cores.
Whether Apple actually delivers a mid-tower remains to be seen, but it wasn't long ago when we thought Apple would
never deliver a low-end headless Mac, but the Mac mini was announced to most everyone's surprise!