The Yahoo Japan comment is interesting. Yahoo Japan is completely separate from Yahoo Inc -- Yahoo Inc owns 34% of Yahoo Japan, Softbank (A Japanese conglomerate and major telco in Japan) owns 41%. It's a completely independent, publicly traded entity, of which Verizon wouldn't even be getting a controlling or even largest shareholder position in.
It's an odd thing, sort of like saying "we'll buy your web, oh and also a really good investment position - we'd like that too".
Yahoo Japan is valued at ~25B USD... and Yahoo Inc is valued at ~34B USD. That would suggest that without Yahoo's 31% stake of $8.5B in YJ, Yahoo Inc would be worth less than Yahoo Japan.
It could very well be that Verizon is buying their Yahoo Japan position and taking their web business as part of the deal, rather than the other way around.