Don't be naive, by son he means he's part Quincy, nothing more, nothing less. If Juha ends up being Ichigo's father then the series, while looking like getting back to something like its best, will have descended into lameness that it almost hadn't yet, apart from making Aizen a butterfly and the whole Fullbring arc.
I find this whole Ichigo being part Quincy very disappointing. I mean, the main character is always somebody special, but for fuck sake making him every God damn type of "race" in the series is too damn over the top. Shinigami, Hollow and now Quincy? GTFO.
Oh well, it's not like I'm going to drop the series or anything, hopefully the story behind Ichigo's mother is interesting at least. And we still need to find out the deal about Isshin too! Hopefully all will be reveled in one hit, like with Naruto finding out about his parents.