download here:

http://www.microsoft.com/windows/windows-7/download.aspx

XP mode (beta) is officially live here:

http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=0e8fa9b3-c236-4b77-be26-173f032f5159

XP mode needs a processor "capable of hardware virtualization, with AMD-V™ or Intel® VT turned on in the BIOS." I wasn't sure what AMD chips supported this, so I did some quick googling. As per wiki.xensource.com, "The desktop processors must be for the "socket AM2" (or above) with support for DDR2 memory and K8 Rev. F2 stepping and above (F3,G1,G2,Tri- and Quadcores) that are not Sempron brand. Server processors supporting SVM include all Opterons for Socket F (aka Socket L1) with 4 digit product numbers (Opteron 1210, 2210, 8210, ...), again here with support for DDR2 memory."

Examples of supported processors are:

    * all AMD Athlon™ 64 processors above 4000+
    * all AMD Athlon™ 64 X2 processors above 4800+  (6400+ yay for me!)
    * all AMD Athlon™ X2 processors
    * all AMD Athlon™ X2 BE, LE, EE processors
    * all AMD Phenom™ X3 and X4 processors

Notebook processors that are branded Turion 64 X2 and Turion Ultra

    * Turion™ 64 X2 TL-60
    * Turion™ 64 X2 TL-56
    * Turion™ 64 X2 TL-52
    * Turion™ 64 X2 TL-50
    * Turion™ Ultra ZM-80, ZM-82, ZM-86

AMD Opteron™ with DDR2

    * 1000 Series
    * 2000 Series
    * 8000 Series

So for what it's worth..... yeah. Have fun with that one, I know I will.

Information for Intel CPU support at http://blogs.zdnet.com/Bott/?p=946

Handy Reference Table

Desktop CPUS
Core 2 Duo     
E4300/4400/4500/4600/4700     NO
E6300/6320/6400/6420/6540/6550     YES
E6600/6700/6750/6850     YES
E7200/7300/7400/7500     NO
E8190     NO
E8200/8300/8400/8500/8600     YES
Core 2 Extreme     
QX6700/6800/6850     YES
QX9650/9770/9775     YES
X6800     YES
Core 2 Quad     
Q6600/6700     YES
Q8200/8200S/8300/8400/8400S     NO
Q9300/9400/9400S     YES
Q9450/9550/9550S/9650     YES
Core i7/Core i7 Extreme     
I7-920/940     YES
I7-965     YES
Pentium D/Pentium EE     
805/820/830/840     NO
915/925/935/945     NO
920/930/940/950/960     YES
955/965     YES
Pentium for Desktop     
E2140/2160/2180/2200/2220     NO
E5200/5300/5400     NO

Mobile CPU products
Core 2 Duo Mobile     
L7200/7300/7400/7500     YES
P7350/7450     NO
P7370     YES
P8400/8600/8700/9500/9600     YES
SL9300/9400/9600     YES
SP9300/9400/9600     YES
SU9300/9400/9600     YES
T5200/5250/5270/5300/5450/5470     NO
T5500/5600     YES
T5550/5670/5750/5800/5850/5870/5900     NO
T6400/6570     NO
T7100/7200/7250/7300/7400     YES
T7500/7600/7700/7800     YES
T8100/8300     YES
T9300/9400/9500/9550/9600/9800     YES
U7500/U7600     YES
Core 2 Extreme Mobile     
QX9300     YES
X7800/7900     YES
X9000/9100     YES
Core 2 Quad Mobile     
Q9000     YES
Q9100     NO
Core 2 Solo     
SU3300/3500     YES
U2100/2200     YES
Core Duo     
L2300/2400/2500     YES
T2050/2250     NO
T2300/2400/2500/2600/2700     YES
T2300E/2350/2450     NO
U2400/2500     YES
Core Solo     
T1300/1400     YES
T1350     NO
U1300/1400/1500     YES

This would mean the bios would have to support it as well, right? If there's no option, there's no support.... right? I don't recall seeing any option to turn anything on or off, meaning it's always on or it just isn't there.

Am I overthinking this?

Game over man, GAME OVER!!!!! 

From TFA:

The new Windows Virtual PC (now available as a beta release for the Windows 7 Release Candidate) requires hardware-assisted virtualization. For your PC to run XP Mode in Windows 7, the CPU has to support Intel Virtualization Technology (Intel VT) or AMD Virtualization (AMD-V), and this support has to be enabled in the BIOS.

E8600 woot.

Well I thought I'd be trying this out. I got everything installed and went to run VXP and got greeted with the nice little message that tells me hardware virtualization is not enabled in my BIOS. There are several options in my BIOS to enable/disable hardware virtualization support and all of them are turned on, so I don't know what else it wants. This is on a Dell Optiplex 755. I checked for a BIOS update that would add additional support, but I'm only one version off the current revision and there's nothing in the new version about virtualization support. So I guess I won't get to try this out afterall.

As for the new taskbar, I found a couple things out during the beta regarding this new-fangled taskbar. First off, I'm pretty sure those who have used Beta already know about the new quicklaunch and taskbar pinning. Some of you may have noticed that when clicking a quicklaunch icon, it uses that icon to expand itself onto the taskbar. You may have thought to yourself, "Well that's stupid, now I can't use that icon to open a new instance!". Bzzzt! Wrong! Middle-clicking a task creates a new instance, as does shift-left clicking.

I never used quicklaunch in any of the previous Windows OS's. But this is definitely awesome, along with the ability to drag tasks along the taskbar.... which is a feature that SHOULD have been there since Windows 95.

Other hotkeys: http://brandonlive.com/2009/01/10/windows-7-beta-hotkey-cheat-sheet/

Oh snap, you can update the beta WinXP SP3 through windows update. HA!