I spec'd out the OptiPlex 980, as well as the 8100 and two versions of the 9100 (from both the Home and Small Biz stores. 
The processors that are in play are:
i7-960 processor(8MB L2 Cache, 3.20GHz) (The 980X is $1000 more: can't do that)
i7-930 processor(8MB L2 Cache, 2.80 GHz)	
(These are on the 9100: the 960 is $470 more than the 930)
i7-870 processor(8MB Cache, 2.93GHz)
i7-880 processor(8MB L2 Cache, 3.06GHz)
(These are on the 8100: the 880 processor is $350 more than the 870). The 870 is also the top option on the OptiPlex.
I don't like that the OptiPlex only has a 305W PSU and I'd likely want to add a blu-ray burner.
Which of these makes the most sense? I do not play any games at all; use CS5 heavily, which is why I want Nvidia.
I really wonder whether the upgrades for the faster processors make sense from a cost standpoint. In all cases I'd add an Audigy sound card.
Specs/Price:
Option #1: 9100: $1690
PROCESSOR 		Intel® Core™i7-930 processor(8MB L2 Cache, 2.80 GHz)	
OPERATING SYSTEM	Genuine Windows® 7 Professional, 64bit, English	
MEMORY			8GB Dual Channel DDR3 SDRAM at 1333MHz - 4 DIMMs		
VIDEO CARD		NVIDIA GeForce G310 512MB DDR3	
HARD DRIVE		        1TB - 7200RPM, SATA 3.0Gb/s, 16MB Cache		
ADDITIONAL HARD DRIVE 1TB - 7200RPM, SATA 3.0Gb/s, 16MB Cache	
OPTICAL DRIVE		
Dual Drive: Blu-ray Disc Drive (BD/DVD/CD burner w/double layer BD write capability) +16X DVD+/-RW		
SOUND CARD		THX® TruStudio PC™	
SERVICE PLAN		1 Year Basic Service Plan	
SECURITY SOFTWARE	McAfee SecurityCenter, 15-Months	
DATASAFE ONLINE BACKUP	Dell Online Backup 2GB for 1 year	
OS RECOVERY MEDIA	Recovery DVD for Windows® 7 Professional OS, 64bit, English	
--> with Intel® Core™i7-960 processor(8MB L2 Cache, 3.20GHz) $470 more = $2160 total
PSU = 525W
Option #2: 9100: $1815
PROCESSOR		Intel® Core™i7-930 processor(8MB L2 Cache, 2.80 GHz)	
OPERATING SYSTEM	Genuine Windows® 7 Professional, 64bit, English	
MEMORY			8GB Dual Channel DDR3 SDRAM at 1333MHz - 4 DIMMs	
VIDEO CARD		ATI Radeon HD 5870 1GB GDDR5	
HARD DRIVE		        1TB - 7200RPM, SATA 3.0Gb/s, 16MB Cache	
ADDITIONAL HARD DRIVE 1TB - 7200RPM, SATA 3.0Gb/s, 16MB Cache	
OPTICAL DRIVE		
Dual Drive: 
Blu-ray Disc Drive (BD/DVD/CD burner w/double layer BD write capability)
+16X DVD+/-RW	
SECURITY SOFTWARE	McAfee SecurityCenter, 15-Months
SOUND CARD		THX® TruStudio PC™	edit
WARRANTY AND SERVICE	2 Yr Ltd Warranty, On-site Service, and 2 Yr Tech Support
--> with Intel® Core™i7-960 processor(8MB L2 Cache, 3.20GHz) $470 more = $2285 total; would replace video card (~$150-175) to get Nvidia card
PSU = 525W
Option #3: 8100: $1554
PROCESSOR		        Intel® Core™ i7-870 processor(8MB Cache, 2.93GHz)	
OPERATING SYSTEM	Genuine Windows® 7 Professional, 64bit, English	
MEMORY			8GB Dual Channel DDR3 SDRAM at 1333MHz - 4 DIMMs	
VIDEO CARD		nVidia GeForce GTS240 1024MB GDDR3	
HARD DRIVE		        640GB - 7200RPM, SATA 3.0Gb/s, 16MB Cache	
OPTICAL DRIVE		Dual Drives: Blu-ray Disc (BD) Burner (Writes to DVD/CD/BD) and DVD+/-RW	
SECURITY SOFTWARE	McAfee SecurityCenter, 15-Months	
SOUND CARD		THX® TruStudio PC™
WARRANTY AND SERVICE	1 Yr Ltd Hardware Warranty, InHome Service after Remote Diagnosis
--> with Intel® Core™i7-880 processor(8MB L2 Cache, 3.06GHz) $350 more = $1904 total
--> PSU = 375W; with this option I'd add a 1TB HD for ~$80 since Dell's option is $300 (!!!)
Option #4: OptiPlex 980 Mini Tower: $1767
BASE/ POWER SUPPLY	OptiPlex 980 Minitower for Standard Power Supply 
OPERATING SYSTEM	Genuine Windows® 7 Professional w/XP Mode,No Media, 64-bit, English	
PROCESSOR		        Intel® Core™ i7 Quad Core Processor 870 with VT (2.93GHz, 8M)	
MEMORY			8GB DDR3 Non-ECC SDRAM, 1333MHz, (4 DIMM)	
HARD DRIVE		        160GB 10,000 RPM 3.5" SATA, 3.0Gb/s Hard Drive with 16MB Cache	
2ND HARD DRIVE		1TB 7,200 RPM 3.5" SATA, 3.0Gb/s Hard Drive with NCQ and 16MB Cache	
VIDEO CARD		1GB NVIDIA GeForce GT330 (1 DP & 1 DVI), Full Height	edit
OPTICAL DRIVE		16XDVD+/-RWand16XDVD,SATARoxio Creator™ CyberlinkPowerDVD™NoMedia	
WARRANTY & SERVICE	3 Year ProSupport and 3 Year NBD On-Site Service	edit
SYSTEM RECOVERY OPTIONS	Recovery Media for Cyberlink Power DVD™ and Roxio Creator Dell Edition for DVD+/-RW	
SYSTEM RECOVERY OPTIONS	Recovery Media for Genuine Windows® 7 Professional,64bit,Multiple Language	
SYSTEM RECOVERY OPTIONS	Resource DVD - contains Diagnostics and Drivers
--> PSU = 305 W; I don't like that this only has one optical drive and no blu-ray. Also has a much smaller boot drive, which isn't really an issue. (I went with the smallest boot drive available in all cases.)