I've heard of experiments like this before though. The problem as I see it however is that Ai logic isn't quite there yet.
A robot could go around objects and likely with satnav find places (although given satnav accuracy isn't quite what it should be right now that could be interesting), however firstly how would it spatially compensate for your size and movement? since obviously a guide dog has to be looking out for your head as well as your feet, has to leave enough room to guide you and the dog around objects, has to watch for sticking out handles etc, all factors which require actual judgement and spacial logic on the dog's part, especially since manifestly the situations one encounters in dayly life aren't necessarily consistant, EG roadworks etc.
Secondly, and most critically is the fact that dogs, like humans can perform broad category judgements from fairly lose sets of criteria. For example if I tell Reever in a shop "find the counter", it doesn't matter whether that counter is metal or glass, what hight the counter is, whether it has a display of things on it or not, whether it has a cash register on it or not, whether there is a person behind it etc. She can perform exactly the same sort of instant soft categorisation that a human can, putting together a large range of factors to interpret the idea of "counter", she even associates the bar in a pub with the word "counter" as well.
She can do this with a lot of objects and even basic concepts, for example she will find "home" even when we're staying in a hotel, going as far as taking me to the door of a hotel room, and will find "out" meaning find the exit we came in by, aside from more mundane objects like "find the bus stop", "find the door", or "find the steps"
Judging with the way AI recognizes objects, I don't think we're yet at the point where the basic pattern matching that is used could get around to these sorts of concepts, especially ones like "home"
Its an interesting idea, but to me guiding just seems too necessarily built on the need for category judgements and logical assumptions to be something which Ai could cope with.
What I do think would be a good idea would be an increase in matters such as satnav control and directions to places, with an Ai use to find routes and accurate satalite information to tell you where you are, since one thing a guide dog cannot do is read a map .
Of course this is also leaving aside the fact that even if a robotic guide dog were developed, aside from all practical concerns of what it would run on, how it would cope with different physical surfces etc I'd be willing to bet the price would be so prohibitively, insanely expensive nobody could afford one privately anyhow.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)