It's very likely that a spacecraft similar to MRV/RSGS could do a life extension mission on Hubble. But, unfortunately, Hubble is in a very different orbit than MRV/RSGS is, so we wouldn't be able to reach it.

"Does the satellite servicer need its targets to be constructed to some common standards, or is the new capability now leading to common standards?"

We can do life extension missions on client spacecraft that were not designed to be robotically compatible. That's actually SpaceLogistic's primary business case.

The question of standards in the spacecraft industry is a huge question. It's being worked... by a lot of people, cue the obligatory XKCD reference.

"Was it built with a method for itself accepting refueling?"

We are, in fact, refuelable.

"It seems to me this device would lead to a revision in satellite reliability design and life calculations."

We hope so! Spacecraft are expensive in large part because they have to be designed to be incredibly reliable. The example I use is cars. If you had to design a car that could go for half a million miles without ever having a part replaced, you could. It would just cost a billion dollars. But that's how we design spacecraft today. IF we can create a "mechanic safety net", we might be able to bring the cost down significantly.