Apple is getting out of the rack-mounted server business and will look to move its server customers to its Mac Pro and Mac Mini server product lines.

According to a document posted on Apple’s Web site Friday, its Xserve 1U rackmount servers will be discontinued at the end of January. The company will continue to offer in-warranty and extra-warranty support and parts, the company said.

But at a time when there are signs that Apple is finally taking its business customers (current and potential) seriously, are its alternatives to the Xserve a logical fit?

The 1U Xserve boasts Intel Xeon processors, as does its heir apparent in the Apple lineup, a server version of its Mac Pro workstations. The new standard Mac Pro Server features a 2.8 GHz quad-core processors with 8 GB of RAM, two 1 TB hard drives and the server version of Mac OS X. (At press time, the Canadian Apple Store had not been updated with any information on the new Mac Pro Server.)

In terms of actual power, the Mac Pro can be tricked out to have more juice than the Xserve, topping out with additional memory and storage, and offering up to 12 processing cores in a single system. The more space-constrained Xserve offered eight cores as its maximum.

But the Mac Pro Server option falls far short of its predecessor in one of the biggest concerns of data centre operators – computing and storage density. System for system, the Mac Pro can beat out the Xserve, but in terms of density, the Mac Pro is a tower form factor and a big and bulky one at that, coming in at 12U.

The end of Xserve also means the end of other data centre-friendly features in Apple’s server lineup, including support for dual redundant power supplies and lights-out management.

The Mac Mini server was just revised earlier this year, and the company positions it as its alternative for small businesses and workgroups of 50 users or less. It comes in significantly cheaper than either the Xserve or the Mac Pro, but also packs a lot less punch, opting for a laptop- or desktop-grade Core 2 Duo processor rather than Xeons, and offering comparatively limited on-board storage options.

Still, Apple promotes the Mini as an option with lower power consumption. Unlike the more power-hungry Xserve and Mac Pro systems, the Mini can be supported with a low-end, low-cost UPS in case of power outages, the company notes.

Xserve first debuted as Apple’s rackmount server offering in May 2002, and was last updated in April 2009. On the storage side, the company has said it will continue to ship its 160 GB, 1 TB and 2 TB drive modules “through the end of 2011 or while supplies last.”

One thought – just a guess – on potential motivation here: Given the persistent rumor that Apple is looking to quickly double up on its already-gargantuan data centre in North Carolina, could it be that Apple is taking Xserve off the market to fill its own orders first? It would certainly help the company ramp up its data centre – which almost certainly requires the higher density offered by Xserve – more quickly, while giving them a chance to gauge just how much demand there is (or isn’t) in the market for rack-mounted Mac servers.