Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
Consumer Electronics Show 2010 (CES) Kicks Off this Week
The launch of the Google Nexus One phone is planned for January 5th, while Apple is rumored to be announcing their tablet device on/around January 26th.
For our part, MacRumors will be attending CES for the first time this year. In the past our focus has been Macworld Expo which has tended to run concurrently with CES. This year, however, Apple withdrew from Macworld which resulted in it being rescheduled into February. We'll be focusing on any relevant Apple-related announcements including new Intel chips, ARM-related technology, notable 3rd party Tablets and more. CES 2010 runs from January 7th - 10th.