Electrical at Waterloo is definitely what you want to take, Peter, so do so with absolute confidence you're doing the right thing.
While in Ontario high school and college programs there is a lot of cross-over in the electrical/electronics and computer curricula, at universities in Ontario there tends to be much more distinction between electrical/electronics and computer engineering departments. From what I've seen of the computer engineering programs (students' group and individual projects), those tend to be focused on creation of things like virtual models or else instead on what I would call the civil engineering side of electronics engineering. That's not what you want if you want to design circuits, your own ICs, build your own CNC, build a robot army, etc.
Electrical is in a nice pocket right between computer and mechanical. As already mentioned, pretty much everything you need to know about computer engineering you can pick up as you go. Software is always going to be changing, so everyone runs a constant hill up the learning curve everytime a new program comes out. The laws of electricity and mechanics, however, are always going to stay the same, so you're better off dedicating your opportunity for intense study at university in one of those areas. So take electrical, dabble in computer as a hobby as you go along, and buy your friends in mechanical a beer once a week (they'll be the ones building your robot army, and they're the most fun to party with).
Chances are your first job out of uni is going to be in Ontario. For that reason, I highly recommend Waterloo. Waterloo graduates' cred with engineering employers in that province (and arguably the rest of Canada) is unsurpassed. This is a non-partisan comment on my part, as I've never attended Waterloo (or any engineering program, so keep that in mind, but I dare say that if you look into what I'm telling you you'll discover it's all true), it's just what I've both seen from students of various programs and what I've heard from both engineers and employers. Waterloo grads are automatic first draft picks, which is part of why the standards are so high for getting in in the first place.
To give you an idea of the context of my comments, I've got degrees from UWO, U of T, and York. The lion's share of my impression of Waterloo has come from engineers who have worked with grads from that program, but who themselves attended school elsewhere (mostly in England), so I feel pretty safe in stating that my views are non-partisan. Based on what I know and you've said you'd like to do, electrical at Waterloo is the way to go.
Incidentally, tell people you've been "accepted" not "excepted" to the programs you've applied to. The meaning of each word is arguably contradictory. Sorry, that's the English teacher in me, but you'll find profs in engineering are fussy over such things too, I'm sure.