I spent Thanksgiving weekend in Ohio, where our local paper ran a quite interesting story about the chaos that can ensue for his/her clients when a lawyer dies or is disbarred. If the lawyer is part of a firm, the other lawyers at the firm generally have an obligation to continue the representation; but if the lawyer works alone, there's nobody automatically designated to take over. Lawyers are encouraged, and sometimes required, to name a "surrogate" lawyer in the case of their death, but like all death-planning this does not always happen, and apparently the surrogates are often not compensated.
1: It's nice to see a long, interesting, insightful article by a local journalist. I'd never heard of the author, Jim Hannah, but I'll be keeping an eye out for his future work.
2: One interesting question is whether there's a case for state intervention here — either by requiring surrogates to be named (as I gather many states do) or providing state compensation for them (perhaps coming out of bar dues).
The obvious libertarian take is that such a regulation is unnecessary or even counterproductive. The risk that your lawyer will suddenly die or be disabled is one of the risks you take when you retain a solo practitioner, and presumably makes solo practitioners slightly cheaper.
That said, consumer information about lawyers is pretty bad, and the market for lawyers is already so heavily regulated that it may be too late to analyze marginal regulations in pure libertarian terms. (In economic terms this is the problem of the "second best.") I do think such regulations are probably a bad idea, but I'm not sure I can prove it.