The Lumia 920, which is a Rogers' exclusive, will fetch $99.99 with a three-year contract and $549.99 on a month-to-month plan. The HTC 8X's pricing, both for the 8GB and 16GB versions, has not been annouced yet. Also absent from the Microsoft post was any mention of Samsung's ATIV S, which was announced alongside the 920 and 8X back in October.
Interestingly, the post has since disappeared. One theory behind the post being pulled is that Microsoft may have jumped the gun in announcing the launch date before the carrier had a chance to. Another possibility is that the post was removed because the Lumia 920 pictured was red, which would be misleading to consumers because Rogers' 920 will be offered exclusively in black.
Whatever the reason, the information seems to be accurate, according to Rogers forum users who have reported being given the same launch date by Rogers representatives.
The Lumia 920 has had a very limited release on Rogers with some stores getting early but limited inventory--a "soft launch" if you will. The full launch is expected to happen very soon.
Update: Pricing for the 8X was also leaked: 8GB in Black $49 (3yr), $499 (month-to-month); 16GB in Blue $99 (3yr), $549 (month-to-month)