That's marketing to a smarter than normal consumer, which is what initially negatively impacted the PSP. Remember everybody b***hing about buying UMD movies and the battery life, when all the smart people were ripping their DVD's and dumping them to the memory stick with Handbrake or another utility.
In addition if the PSP2 could be used with a wireless service, it seems obvious that Sony would push that angle of the market for it.
Also this assumes you have a phone that uses a SIM card.
PSP is fine with VOIP / Skype IMO.
I haven't been keeping up with the Joneses, what exactly does the Nintendo DSi do that the old ones didn't?