The PSP remained on top of the Japanese hardware sales chart, this according to research group Media Create. Nintendo plans on replenishing it's lacking DS supply by the end of the month, so it should be interesting to see how the restock affects subsequent charts.
Japanese sales (units sold) the week of 1/9/2006 - 1/15/2006:

1. PSP - 57,686
2. NDS - 54,284
3. PS2 - 39,076
4. GBASP - 9,982
5. GBM - 6,341
6. X360 - 6,107
7. GCN - 5,465
8. GBA - 233
9. XBX - 119