Sigma 70-300 f/4-5.6 APO OS Macro
The new Sigma lens would replaced the 70-300 f/4.5.6 APO Macro with a stabilized version.
Announcement expected this week.
The only rumor I have received about Sigma comes in the form of an 85 f/1.4 being announced. It's an older rumor.
Tamron & Tokina
I haven't received any information for a while about these companies.