The mystery of the iPhone 3G SMS rates

In a previous piece I published information about AT&T's new iPhone 3G rate plans:

Individual voice plans:

• $39.99 – 450 minutes
• $59.99 – 900 minutes
• $79.00 – 1,350 minutes
• $99.99 – unlimited minutes

Family Talk voice plans:

• $69.99 – 700 shared minutes
• $89.99 – 1,400 shared minutes
• $109.99 – 2,100 shared minutes
• $149.99 – 3,000 shared minutes
• $199.99 – unlimited shared minutes

As has been well publicized, AT&T increased the unlimited data rates by US$10 – from US$20 to US$30 per month. AT&T previously included 200 SMS messages with their individual and Family Talk plans and charged US$20 per month for unlimited SMS messages.

Other than the $10 increase for 3G data, AT&T hasn't announced the rate plans yet for SMS. Rumor has it that AT&T will unbundle the included SMS messages and instead charge US$5 per month for 200 messages and US$20 per month for unlimited SMS messages.

So with a US$5 upcharge for SMS and US$10 for 3G data, is AT&T nickel and diming us to death? How much are you willing to pay for SMS?