Just to get you guys notified, all DS Phat users will be happy. They have released a lot of new replacement cases for the NDS Phat at a range of $6.35 to $7.49 USD at DealExtreme. I have organized the cases by design/box.

Group Descriptions:
Group 1 - Manufacturer 1
Group 2 - Manufacturer 2, Black/White Bottom, Color Top
Group 3 - Manufacturer 3, Full Color (Means one color for whole case), has NDS Logo

There are too many pictures to post but here are the links:

Group 1:
Full Replacement Housing (Pink) $6.35 USD
Full Replacement Housing (White) $6.35 USD
Full Replacement Housing (Black) $6.35 USD
Full Replacement Housing (Red) $6.35 USD
Full Replacement Housing (Electric Blue) $6.64 USD
Full Replacement Housing (Silver) $6.77
Full Replacement Housing (Icy Blue) $6.90 USD

Group 2:
Full Replacement Housing Case with Buttons and Screws for NDS (Silver + Black) $7.49
Full Replacement Housing Case with Buttons and Screws for NDS (Smalt + Black) $7.49 (Says Smalt, But I think it is Electric Blue)
Full Replacement Housing Case with Buttons and Screws for NDS (Sky Blue + Black) $7.49
Full Replacement Housing Case with Buttons and Screws for NDS (Scarlet + Black) $7.49(Brighter than Red)
Full Replacement Housing Case with Buttons and Screws for NDS (Red + Black) $7.49(Darker than Scarlet)
Full Replacement Housing Case with Buttons and Screws for NDS (Gold + Black) $7.49
Full Replacement Housing Case with Buttons and Screws for NDS (Icy Blue + Black) $7.49(Look like Icy Blue to me.)
Full Replacement Housing Case with Buttons and Screws for NDS (Pink + White) $7.49

Group 3:
Full Replacement Housing Case with Buttons and Screws for NDS (Silver) $7.49
Full Replacement Housing Case with Buttons and Screws for NDS (Rose Pink) $7.49
Full Replacement Housing Case with Buttons and Screws for NDS (Icy Blue) $7.49
Full Replacement Housing Case with Buttons and Screws for NDS (Gold) $7.49

 

Short version, other than ebay no. However I got one from a UK based supplier and did a review of sorts a couple of months back, it is holding up very well despite falling off my desk several times.
http://gbatemp.net/threads/ds-original-phat-replacement-case-review-56k-no.364632/#post-4969164
Original thread that spawned it
http://gbatemp.net/threads/original-ds-replacement-cases-in-2014.364457/

However I just checked the supplier I used and they no longer stock them, I see a few of the same model on UK ebay/out of the US though hence this reply. I also see a full pink DS for probably less than that plus shipping.