I will admit, however, that this was not a premeditated "replacement" for the guinea pigs. The bunny in question ===> (presently named Thumper, although the continuation of that is under debate) has been living with us for a month. She was the pet of one of Daughter #2's close friends, who was going on a long vacation, and we were "bunny sitting" for her. Daughter #2 had some experience with bunnies, having done vacation duty on another one that lives in the building while its family goes out of town, so taking in Thumper for the month of July wasn't a huge imposition.
Now, I don't know the specifics, but it appears that something was changing in #2's friend's situation, and they were not going to be able to keep the bunny. So, instead of them coming to pick up Thumper last week, they were casting around for some place to, essentially, dump said bunny.
It's hard to attribute too much perception to a creature with that small a brain case, but I got the feeling that Thumper was very clear on how her situation was developing ... from having been getting excited (about having "her family" coming to get her), to being morose (when it became clear that they weren't). Initially she was very hostile to us, but she's become MUCH friendlier of late as well. I was feeling rather bad for the bunny ... since I'm sure it was not a happy day when her family dropped her off here, and not getting to go back to what she knew I'm sure was sad. Plus, without our stepping in, the plan appeared to be them finding anybody who'd take Thumper off their hands, even (perhaps) somebody with an extensive Hasenpfeffer recipe collection. I guess The Wife was also feeling badly for the bunny's prospects, and eventually told Daughter #2 that if she wanted, we could keep Thumper.
Over the next week we're going to be re-working the guinea pig cage (which is a lot larger than Thumper's current environment), and possibly adding another level to it (as Thumper is a lot taller than Ginger and Paws were, and seems to favor hanging out on this raised platform in her cage). We're going to have to learn a new routine (cleaning up after a bunny is different from cleaning up after guinea pigs, and their diet is a bit different), but Thumper is fairly young, and so we're likely to have her around for 5-10 years.
Oh, and you can click on the pic of her for a much larger version.