Hm, my answer is a little longer, so I better write it down here.
I'm not particularly interested in either of these titles, because I already know how to get started in OpenSim, and have no intentions of running a grid. That is not to say that these books could be very useful for many people; I'm just not one of them. So if your intention was to scope out the potential range of readers, I have to answer simply "not interested".
However, I think books about OpenSim are sorely needed. Simply because books about *anything* on the internet are sorely needed. For us living in virtual worlds it might be sometimes hard to imagine, but there's still a large part of the population, even in "broadband" countries, that don't engage in online activities in any meaningful way. I know this because I've got lots and lots of examples in my own family; if I had to estimate a guess, I'd say at least 50% of my family (and not just the "old and downtrodden") aren't computer or internet-savvy. And this is a family that has at least one long-time hacker among them (me), even though I am just more or less the Microsoft Support Team for them.
The problem is, when a book has "opensim" or "grid" in the title, you're catering to a very small subgroup of an already small enough niche, and chances are, the people who recognize these terms are the people who already know most of what you're going to write about. From the times I've spoken about OpenSim to audiences who were not active or interested in Virtual Worlds (even though they were definitely computer savvy), I've found the biggest problem is not explaining how OpenSim works and what to do to get a grid up and running; it's telling them why OpenSim matters, why we think this is a great and important technology that will shape our future, and why it's not bloody enough to have facebook.
So, I think we need books about that. Even though I already am on board of that particular bandwagon, I think we sorely need texts that talk positively about the cool things that can be and are being done in Virtual Worlds. And since books particularly appeal to the kinda-computer-savvy-but-not-online-all-the-time crowd, I think the (e)book format is the right thing for them.
Now the other problem is how to sell it to them, but that's the issue with every book, isn't it?