wow, some of the comments on here are dense.
screen real estate and high power are not necessarily linked.
I am an IT professional, and I use dual monitors to keep track of many simultaneously open windows, in several different "spaces".
But I don't do rendering, I don't do video editing, I don't do audio processing, I don't do digital drawing, or database crunching on my workstation. I have e-mail, multiple web browsers with database and other interfaces up, office apps, Calendar, and screen sharing for my server, and it is nice not to have to shuffle those windows on one screen.
I don't need high power MacPro stuff, an iMac or a Mac Mini does fine, except for the fact that the iMac is only one screen, and is a bit tall for just one screen, while compromising heat dissipation by sandwiching all that componentry into a big single monitor.
Not only that, but a pair of good monitors can last quite a long time, while computers in an IT setting can get rotated through an upgrade cycle of hand me downs, and various tasks, so it can be nice to have a computer separated from the display or displays it drives.
I have three good uses for a nicely equipped macMini, if they are nicely equipped when they get announced.
1: dual monitor workstation, just as I mentioned. Not heavy lifting, but a good amount of display space.
2: headless screen-shared NetBoot/NetRestore server, for backups and software distribution on my work bench.
3: home theater PC, driving a single HD monitor, and digital input audio receiver.
Three distinct uses that a MacMini, if well equipped and reasonably priced, could not only do well...
but would be better suited to than ANY of the other Macs in the lineup. iMacs are configuration limited by being all-in-one. MacPros are overkill for what I need, and too expensive for those roles. Laptops are too limited, and I don't need a built-in keyboard, trackpad and screen with a very tight space limitation. My users use laptops, and for good reasons, but I have different demands than they do, as support, and in my personal use.