[who_would_fardels_bear]

I think the lilt and the 'So' are basically lame attempts at false modesty.

Basically the twits are saying: "What you're hearing is the absolute truth, but if I tell you that it is the absolute truth you will be offended at anyone claiming to know anything. So instead I'll couch it in such a way that it seems like merely my considered opinion."

[HiTech RedNeck]

It would be in the vein of condescension or irony