Microsoft's Surface Hub videoconferencing systems are going to be pricier and slightly later than originally announced.

In August, Microsoft officials said to expect the 55-inch Surface Hub model to be priced at $6,999 and the 84-inch model at $19,999. On December 22, officials said via an e-mailed statement that they are adjusting those prices to $8,999 and $21,999, respectively.

Customers who already placed orders will still get the original pre-order prices, officials said today.

Microsoft officials are not saying much as to why they upped the prices. The official statement is the company is "finalizing our manufacturing plan with a view towards delivering the best product experience."

"After evaluating the market opportunity and considering the unique collaboration scenarios Surface Hub offers, we believe these are the right prices to drive the business and the category forward," according to a statement from a spokesperson.

Microsoft officials also said last Fall the first Surface Hubs would ship starting January 1. That was a delay from the original target availability date of September 1, 2015.

The new statement is "we are still on track to ship the first Surface Hub devices to customers earlier next year." A spokesperson said the devices will begin shipping in the first calendar quarter of 2016.

Microsoft unveiled its Surface Hub systems in January 2015. Surface Hub is Microsoft's successor to its large-screen Perceptive Pixel displays.

The Surface Hub systems, which run a custom version of Windows 10, are pre-assembled, customized multi-touch, digital-ink-enabled collaboration systems. Both Surface Hub models include custom-designed versions of OneNote, Skype for Business and Microsoft's Office apps. They also will be able to run Universal Windows apps available from the unified Windows Store. Two pens and a wireless keyboard will be part of the systems out of the box, as well.