A press release (PDF) was posted in Japanese on the Akatsuki website this morning with some official information on the mission status. Here is a translation of the text, with help from Kay Previsich and from sei_n, natsu_shigure, and hee913758 on Twitter.
"On December 7, 2010 at 10:28 (JST) [01:28 UTC] we managed to receive a radio signal from Akatsuki. However, further analysis of the radio transmission has confirmed that the orbiter is in safe mode. In safe mode, the spacecraft orients itself to the Sun and is under spin stabilization. The operation to receive and confirm the condition of the spacecraft and its trajectory is in progress. The team will continue to determine the spacecraft's position and status as soon as possible."
Another helpful person on Twitter has told me that the orbit insertion burn was supposed to last 720 seconds. Provided that the burn lasted at least 560 seconds, Akatsuki will be in Venus orbit; if it did not last long enough, it won't be captured. Also, the spin rate is 0.1 rpm; apparently they only get communications during one little 40-second window per 10-minute rotation when the antenna is pointing in the right direction, which would make it difficult to establish the condition of the spacecraft other than "it's awake and talking." But that last piece is critical and gives the necessary hope for recovery. sei_n said it will take several hours to get the housekeeping data off of the spacecraft under these conditions.
Here are a couple of English-language news stories on the Web, but, except for this excellent article from Kelly Beatty at Sky & Telescope they contain no further information than what I have written here. BBC; AFP; Mainichi Daily News.