Everyone else has already replied to this post, but I want to join in too!THe "real currency" thing isn't a good idea imo for any online service. Using a points system means points can be given via promotions, gift cards, even thorugh games. Real currency means a credit card is required. Sony can't offer the same functionality to those without credit cards (which is how the first iteration of xbox live worked).
The 'real currency' thing could be handled many ways, but to me the most obvious solution for Sony is when you create your PlayStation Network account, they create a real bank account at their bank. You'd then have options to credit that account in many different ways. You could pay via a credit or debit card, or maybe even PayPal. You could set up Direct Debit payments or bank transfers. You could buy vouchers/cards with codes and enter them online to credit the account. So in no way at all are they limiting customers to having to have a credit card just because they're using real money. The only difference is the way the figures are represented on screen. On Live! they take your real money and display a virtual currency. On PSN they just show the money as paid instead of converting it to a virtual currency. Whether you buy a card for $5 and enter a code and get credited with a figure for 500 points or $5, the same techniques can be used.
An integrated account will also be better for Sony to sell content, in that users will have credit paid in (accruing interest!) that they can spend on say a music track without needing a credit card as required for other music download services. It'd also give Sony the option to offer credit facitilities too, if they want to go the whole hog and rip off every single penny that can take from customers!
As for the messaging, voice chat/video chat in game is something of a requirement I think for reason others have mentioned. It didn't seem clear though whether the current setup means you have to exit the game to check messages, or pause it and switch to a different menu. If the latter that's no big deal.