Looks like T-Mobile's two new prepaid phones, the Nokia 1208 and 2760, are available online for purchase now. The 1208 is $30, the 2760 is $90 (!). The Nokia 2610 is still available for $30, and the Samsung t219 and t429 are available for $50 and $100, respectively. You can also get the Motorola v195 for $30. No great deals here, just an update.
As for AT&T's GoPhone service, you can still get the Nokia 2610 for $25 with $25 in airtime, $40 with $50 in airtime or $80 with $100 in airtime. Or get the phone alone for $8, refurbished. The rather high-end Motorola v365 is also available, refurbished, for $60. You can also get the Sony Ericsson Walkman w580i, refurbished, in black or pink, for $100. Otherwise you're loking at AT&T's typical, though large, GoPhone lineup and pricing handset-wise.
Yes, I know, I have lots of phones to review, and in response to the silent question of when a review will come up, I have a Nokia 2610 sitting beside me for that very purpose. A 2610 that, mind you, was paid for by the site's sponsors, most likely by BabbleBug. So pay them a visit; they're what make these reviews possible.