Thanks for your feedback. As you noted, the LPY510AL chip is discontinued by ST, so that is not something we have control over. (By the way, those analog accelerometers are getting discontinued, too.) The LPx4xx parts you mention have different packages, so the old PCBs would not work with them at all.
So, the only real option is to design a new board around a new chip. When we choose which parts to work with, we need to consider a range of factors, including what we expect the future for the parts to be. I would not want to invest any effort in those LPx4xx parts since my impression is that ST is not excited about them. It looks like they have some newer (L3G...) analog parts coming out, so we'll keep an eye out for those.
Does anyone else strongly prefer gyros with analog output over digital?