Update: AllThingsD weighs in with its sources today following the Jefferies report:

Sources tell AllThingsD that Apple has indeed had talks with a few large cable operators about some new TV product. It makes sense that one of them might be doing its due diligence on capacity issues and whatnot… But the idea that a “potentially … imminent” launch is in the works seems harder to take seriously.

A new report from Jefferies & Co.’s analyst James Kisner, citing ” discussions with industry contacts” (via Barrons), claimed a new Apple TV product is “imminent” with “at least one major N. American MSO” currently working to find out how much additional capacity would be necessary on its network to handle the new product:

Our discussions with industry contacts suggest that at least one major N. American MSO is working to estimate how much additional capacity may be needed for a new Apple device on their broadband data network. We believe this potentially suggests an imminent launch of the Apple TV, a positive development for ARRIS, who is directly exposed to data traffic growth from incremental IP video streams on cable networks… 

The report does not provide any information about what type of new Apple TV product this would be. It’s possible the cable company in question is testing its network for a rumored streaming service of sorts and not a hardware product. The note also added Jefferies analyst Peter Misek, who several times in the past predicted the launch of an Apple HDTV, is still expecting “sales of 4.9 million units in CY13 and 11.6 million units in CY14″ for a full fledged Apple TV set:

We note that Jefferies analyst Peter Misek is forecasting Apple TV unit sales of 4.9 million units in CY13 and 11.6 million units in CY14. These estimates assume an actual Television product (not a “puck” like the current Apple TV).