I don't know who first found the trademark application of the PS3 controller, but apparently he/she has little experience with the Japanese trademark database.
You can search Japanese trademarks from here
http://www.ipdl.ncipi.go.jp/Syouhyou/syouhyou.htm
and the said trademark for the PS3 controller is Trademark Application 2006-40965. It has 8 images, but all of them are just the drawings of the PS3 controller from different angles.
The trademark section is with the note "(for query)". What is actually written in there as "Trademark (for query)" is actually "§P∞S", not even "P∞S". How to pronounce the trademark is also registered, and it's the same as "PS", no infinity or whatever. So what do those '§' and '∞' mean in the context of the trademarks database? Apparently they are control characters.
To illustrate what those control characters mean we can browse other trademarks. For example H10-58610 by SCE has this image:
Its trademark for query is "§X∞I∞[sai]". '§' in the head means it's an image trademark, not a word trademark. So what does '∞' mean? I think it means it changes where characters are put in a trademark image. Another control character that appears in trademarks is '\', which means CR-LF.
Another question is, why the mere drawings of the PS3 controller have "§P∞S" as the query term. I think it's because the PS3 controller has a button with the PS symbol at the center of it. I can verify this theory since Trademark Application 2005-49788 is for the most famous PS symbol and its query term is also "§P∞S".
Basically, the party is over, we know nothing about the name of the PS3 controller yet