This whole farts analogy is getting out of hand!
As for the screen, there are rumours to suggest there might be a retina display MacBook, sure. Some similar hardware has been spotted and they've been releasing larger icons which may mean they're on the way for sure.
Q2 is pretty early! Ivy Bridge doesn't come out until April afaik, do you really think the MBPs could come out then?
Just feels too soon.
My gut feeling is they won't come out until the autumn is nearly here because we still have iPad 3 and iPhone 5 to get out of the way!
People are always optimistic on shipping dates. IPhone 4S is still new enough. It's unlikely to come before the laptops. For the next iPad I'd just look at scheduled events. Apple is likely to announce that one at a major event. Next thing... do not expect a retina display (even though that's just a marketing term anyway) on a macbook, especially not an ips display like you have on the ipad. IPS panel types have become significantly cheaper, but they're not common at this size, and it's unlikely to be within the budget of a laptop. Devices like the ipad have very low costs for certain items like the cpu/soc. Such a display would be significantly higher in cost for an item like the macbook air or pro which use stock TN panels that cost very little.
How far in advance do Apple tend to announce new MBP's. Do they tend to announce them a month or so in advance, or announce them and they're in the shops the following week?
It's all over the place. Usually they're available for order soon after any announcements (sometimes immediately) but they may have extended shipping times.