To everyone pooh-poohing the reuse of the same/tweaked form sensor, what are you really complaining about? I only became aware of a new 'small Rebel' a couple weeks ago, and wasn't anticipating anything earth shattering.
Were you honestly THAT excited over a small form camera, that you expected a new sensor, and more importantly... were you going to buy it until you saw it was only 18MP? At what point would you have been satisfied (brand new 14MP/16/20/24MP), and if once satisfied with the specs, would you be buying it? If the last answer is ultimately no, which I suspect to be the case for most, then why do you care?
In my opinion, this is a great use of using 'hand-me-down' technology in a business sense, extending the earning power of already existing technology, and is something I expected. Remember this effectively replaces the 12MP sensor of the T3/1100D. If you already have proven successful technology, you are foolish to not exploit every last drop out of it.
The timing of this 'surprise' new body is also good. Ahead of them introducing long anticipated advanced-entry and other niche level bodies (700D/70D/7D2), why is this a bad thing? It means in all likelihood, we are going to see at least 1, maybe 2 if we're lucky, new sensor(s) being introduced to replace what would appear to be a now vacant position in the technology battle.
Also, since everyone knows simply throwing megapixels alone doesn't accomplish much, please ask yourself what would have really made you happy. Maybe we should all wait a couple more days for more news and announcements, and if not then maybe in a month or two.