In a note to clients — as reported by “AppleInsider” (http://www.appleinsider.com) — Morgan Stanley analyst Katy Huberty says if were to launch a full-fledged television set (the rumored “iTV”), it could cause total average annual U.S. household spending on Apple products to double to US$888 by 2015.

She said that Apple’s U.S. household spending doubled following the launch of the original iPhone, from $150 per year in 2007 to $295 in 2010. She expects that the iPad will double that spending again, to an average of $635 per household, per year by 2013.

“Given a 97% TV household penetration and a 61% broadband household penetration in the US along with an expected high price (and value) point, an Apple TV is likely to generate a similar increase in average household spend, with some help from iPad and iPhone growth,” Huberty wrote.