Yes, it's likely that the next camera is launched T6i. I just hope it has the same sensor 70D.
Canon is shrewd when it comes to milking profits from sensors. Consider that the T5i/700D did not get the latest version of the 18 MP APS-C sensor. The T5i's sensor has Hybrid CMOS AF (same sensor as the T4i and the EOS M), whereas the sensor used in the SL1/100D and the EOS M2 has Hybrid CMOS II AF (where the phase AF area covers 80% of the frame vs. just the central portion). That allows Canon to release another T#i-series body with a 'new' (to the line) sensor (but not the 70D's sensor). Put Digic 6 in there, and they're good to go with the T6i/750D.
I doubt it. A 70D body already costs barely more than the current rebel when it is released. What is more likely to happen is that the rebel line will not be updated and the 70D will take that place in the lineup, since it is about the same price point. The top end APS-C will be taken by the new 7D2 (or whatever they call it), and will probably have advanced video features that would allow it to compete in the same space as the GH4. The last of the three speculated DSLRs would then be a full frame camera, replacing either the 6D or 5D3 (probably they would do the 6D first). Full frame cameras have not been updated for some time and are due, if they are to remain competitive.
Canon is in the business of making money, they need their revenue stream flowing and the way to do that is to convince people that it is time to update their bodies. An iterative update will not cut it in that regard, so we can expect something substantial in higher end cameras. Since they have already said that they are going to be focussing on video, what will probably happen are a set of new cameras will incremental upgrades in still capabilities and large upgrades in video capabilities. That is where the growth potential is, and (unless they are stupid) they will capitalize on the current interest in 4K and high quality output to drive that process. While the average Joe might not care about 4K and video quality, the target group that buys their high end cameras most certainly is.
So, at the low end the new Rebel T5 will provide good quality stills for the average Joe (who doesn't care that much about video quality). The 70D will fill the spot in the lineup previously occupied by the Rebel Txi series, with a price drop of 200-300 dollars to get it in the sweet spot. The high end of the consumer market will be targeted by the 7D2 which will have excellent APS-C stills capability and high quality camcorder like capabilities for 1080p video. The prosumer market will be targeted by something like a 6D2/5D4 which will provide excellent full frame stills and high quality 4K capabilities (similar to the GH4). That way they could revamp the entire line and provide something for each of the four main market segments to drive growth.
At the professional level they introduce the new cinema EOS models to address the dedicated film makers. There will be a high end model (8-10K range) for the real professionals, and a lower end model (3-4K range) for the wannabe amateurs.
In addition, in the camcorder segment there will be new 4K camcorders, a semi professional model similar to the HA 20/25 and a consumer model similar to the Vixia HFG30. One or two professional big bucks camcorders will be introduced to address that market segment as well.
If they do this over the course of the next 9-12 months they will revamp pretty much every market segment and keep them competitive, particularly with respect to the changes that video is currently undergoing.
That is my prediction of what will happen.
Where does the SL1 fit into this model?
I don't know about you but the 70D is way more expensive than any rebel I've ever seen, even when newly released, where I live. Also they are targeted at two different types of photographers. I think the rebel / txi line will continue on. It's a big seller for Canon. It's very much their bread and butter camera. The T5 is aimed at the budget conscious and IMO doesn't replace a rebel. It's a great camera though for the price. The SL1 fills the handbag and compact travel needs. Neither of those are a good replacement for a solid, full functional mid sized DSLR for the beginner looking to get into photography. The 70D probably seems too advanced to some of those types of people. That would be a tough choice - a very low budget DSLR, or a $1000 semi pro model. As a newbie or casual shooter I'd want something in between.
The rebel has always been that perfect balance of awesome features and performance at a reasonable price level. I doubt Canon would disturb that strategy.