Wow guys, thanks for all the responses. Seems that everyone has a different way to tackle this issue. I'm disappointed – and a little baffled – that Boeing or Smiths didn't provide a simple "recalc path" selection, maybe in the descent page. I mean, this is a very common issue, at least with the way ATC works here in the USA. It's almost as if no one asked pilots how they use VNAV day-in and day-out. Oh well, whining won't make it any better, so I'll try everyone's techniques once. I especially like plain-plane's RTA speed limits suggestion. I do wonder, however, what to do when ATC issues a speed assignment...will I be able to mod the descent speeds on the VNAV DES page, or will I have no choice but to open the window with SPD INTV? I'll try it and report.
Keep the ideas coming!