Please try to write in English -- other people here who have a different first language (including me) manage to do so.
No, it's not possible as of yet.
With the slow speed of the CPU, it may not be possible even with an upgrade. And even if possible, Sony isn't exactly known for releasing upgrades with added functionality to existing devices.
Well the WIFI implementation in the ux-50 has some serious flaws. It only allows me to connect to Open System Authentication AP's instead off Shared Key Authentication AP's. In effect, no authentication is done. Note, however, that if WEP is enabled on the access point, stations will be able to associate with the access point but will be unable to send and receive data packets unless they have the correct WEP key. With Shared Key Authentication, on the other hand, only stations that have the same WEP key as the access point may associate with it.
But to come back to you question... ( in dutch duh). Nope haven't seen any app for the ux-50 wich does EAP-TLS authentication. Closest ive seen is a VPN solution.. from mergic http://www.mergic.com/ Only PAP, CHAP, MS-CHAPv1, and MS-CHAPv2 authentication where PAP is disabled by default. Why bother to implement it. ? And a pricy solution from meetinghouse http://www.mtghouse.com/products/index.shtml#palm1 . And that's only for the tungsten C.