[citation][nom]Curnel_D[/nom]If they do this, they instantly loose their competitve edge against the 360. I know more than a couple guys who sprung for the PS3 over Xbox because of the free PSN over the expensive XBL.[/citation]
XBL cards can be had for $30 all the time on ebay, which comes out to about $2.50 per month. All you need to do is be on the lookout for them. At the MSRP though, I myself would let my gold membership lapse before paying that.
If Sony wants to start charging for their network use, that's fine, but I would hope they don't have plans to do so with the network in its current form. They really need to invest some money into it first to at least give users a better reason why they should start forking over some money, especially at that $70 price tag.
A note to MS and Sony though: I'd be okay with pricing tiers as long as they give an option to game for free online with absolutely no extra features, I could care lees about them anyway (thinking in the sense of how PC multiplayers are).