They're intentionally trying to get away from that "pairing" by *staggering* their models (with steppings in overall size corresponding to those in model number); it ain't going to be the old way no more.

The new V70 (sure, it *looks* pretty much like the old one -- but then, this is Volvo, spelled c-o-n-s-e-r-v-a-t-i-v-e, we're talking about! :-) is based on a *shortened* S80 platform. (Which coincidentally puts it size-wise pretty much exactly where its predecessor was.) So, no, they *didn't* "keep selling the V70 long after the S70 has been replaced" -- the V70 *was* replaced too, only you didn't notice yet.

All that remains to be seen whether the V50 I'm so (perhaps over-)confidently predicting will be based on a shrunken S60 platform, or a stretched S40 one. Or perhaps the next-generation S40 will be based on a shortened V50 platform. (Which will thus be a *twice*-shortened S60 platform! :-) Whatever...

[From the Dept of Further Over-Confident predictions:] If they do anything with the SUV, it won't be to replace the V70, but to rip off the plastic Jeepy-bits, lower (and maybe stretch?) it a little, and slot it in as a V90 estate *above* the S80 in their line-up. (And yes, Swedish car magazines have been mumbling about a possible future "S100" Über-Volvo sedan to top off the range, for years already.)