So I also think that for Canon's entry dslrs, the writing's on the wall because the only difference in mirrorless bodies is that - well, they're mirrorless, meaning no optical viewfinder. And unless you're old school and rely on that, there's no inherent difference at all.
First off, one of the biggest complaints I have heard about mirrorless cameras IS the lack of an optical viewfinder. EVFs are fine for indoor applications, but they suffer outdoors, lag when panning, and fall behind when continuously shooting. My understanding is that some are better than others and it sounds as if Sony may have beat some or most of that, but I believe that is on the higher priced models (A65?).
Second, I have a T3i and a Panasonic GF3 and I can tell you that, as much as I love the GF3 for what it's good at, it's no replacement for a DSLR, and not because of it's minimal amount of controls. It's biggest disadvantage (to me) is shutter lag, which is why I bought my first DSLR back in 2004 over an advanced compact (which were selling for roughly the same price at the time). When I press the shutter on the T3i, I pretty much get what I see in the viewfinder. With the GF3, not so much. Not that it's terrible, mind you, but there is a noticeable lag (still far better than a typical compact), and I hate not getting what I saw. Now, I don't know how these two particular cameras shake out for hard data on shutter lag, I just know what I experience over and over using both cameras. I don't know if shutter lag is inherent to the mirrorless design or if maybe there are mirrorless cameras out there that can compare to a DSLR, but I'm betting that they are at a price point not competitive with the Rebel line (like maybe the NEX7N).
Having said that, I love the GF3 for what it IS good for and that is much better portability while still delivering much better performance (shutter lag, focus speed) and IQ than the Canon SD790 I was using as a portable camera. Plus, for video it has continuous auto focus (yes, I'm an amateur, and yes, I use the T3i for video as well with manual focus). The live view on the GF3 is worlds ahead of the Canon which for some situations is nice, such as indoors, or when it is more convenient to hold the camera somewhere not at eye level. But, when portability is not an issue, I reach for the DSLR every time. Now, except for a friends two older Olympus cameras, I haven't used any other mirrorless cameras for comparison, but professional reviews I have read seem to all have the same sentiment that mirrorless cameras are great but are not a replacement for DSLRs.
Bottom line, if the entry level DSLRs are threatened by mirrorless, than it would seem to follow that eventually all DSLRs will be threatened (and maybe that's a good thing). I do believe the Rebel line is behind in areas such as live view and continuous auto focus, and I believe they will catch up, but in the mean time, the DSLR still has the advantage overall (to me). My biggest fear is that Canon will abandon the EF/EF-S mount like they did to me with the FD mount on my T-70 way back when.