Only diehard apple enthusiasts will fork out a ton of money for iPanel. This isn't a $199 subsidized iPhone, or a $500-$700 iPad. This will be closer to $2000 for a 42 inch screen. Considering you can get a really good 70 inch Sharp TV for $2000 to $3000 with apps such as netflix, Vudu, etc, Apple will be hard pressed to make a dent in the market that is losing money because $1000 to $3000 for a tv is still a major expense for most consumers, that they keep far longer than a computer. If Apple wants to make an impact, they need to wow the consumer with size. Minimum 60 inch screen, better yet 70 inch, for less than $3000.
I was right there with ya till I got to that part in bold... That doesn't make any sense. People won't want to spend a lot of money on an Apple branded TV so lets make it bigger and more expensive??

Plus a lot of people just don't want/need 60-70" screens. I have a 55" and that is big enough. This iPanel rumor referenced the price being $1,250, so if that's true that would be a much easier pill to swallow.
But I agree that it would be difficult to get non apple fanboys to bite on the iPanel at least for a while. iPad was a new product, Phones are replaced every couple years anyway, but not a lot of people are going to drop everything to go purchase an iPanel when their current TV works great. That's why the Apple TV will serve as a crucial "gateway drug" to the iPanel.
This is what I would advise (assuming this iPanel rumor is correct for a May/June production cycle with a release in time for the holiday season)
At WWDC in June iOS 6 is announced, which includes a huge upgrade to Apple TV complete with an App Store and many other features which will be major selling points for the still unannounced iPanel.
July/August Apple holds a media conference to announce the iPanel. It will include all the functionality of the Apple TV while adding a few major additions (Siri, facetime, motion controlled, etc)
iOS 6 (along with new iPhone) is released first week in october
iPanel is released in early November.