Thanks a lot guys for your answers.
As Fraac puts it, there have been many threads dedicated to the subject. I've found the following ones really interesting :
http://www.wrongplanet.net/postt172748.html, http://www.wrongplanet.net/postt164056.html, http://www.wrongplanet.net/postt120583.html, http://www.wrongplanet.net/postt159612.html
From what I've read, here are my feelings :
As a webmaster, I will learn JavaScript/ECMAscript, PHP, MySQL, XQuery.
I'm still wondering wether to go for PHP OR Perl, can you help me on that please ? I've read several times that PHP, while esay to learn and powerfull, could results in badly coded web-applications due to its "forgiveness". On the other hand, I remember CGI scripts in Perl (mainly form processing) that seems to be very fast. The day I discovered the Iagora website, entirely written in Perl, I thought I would go for it.
Thing is, from what Fraac said, it seems to be "not so compatible" with other language learning, but why ?
As for the rest, I'm on the "old school" way of seeing things : I used to like the5k design contest and the likes, I was fond of coding parties (as public). All the Amiga and Atari demo scene and makers blew my mind away, coding demos that were stored on 3'5 floppy disks, it was *just* amazing. Nowadays programming interfaces seems to need more and more RAM and CPU units, unrelated to the vision of a "nicely crafted / engineered" soft.
Therefore, I would like to pick up the right tools. I've seen too many arguments againts Java and ALL Microsoft programming languages. Fortunately (sic), I'm not doing it as to earn a living.
I would go for Pascal/Delphi, Lisp, C...
My goal is then to write softwares that could manage and store all my web works. I do a lot of SEO (as a living) and would like to automate web-related tasks (like checking backlinks.)
And last but not least, I will try to learn ASM, in order to have a grasp of the inner bits of CPU. What would you recommend ? I have a few old PC, but it seems to have many ASM versions around.
Thanks again for taking the time to reply if you read something wrong in my choices/assomptions, or just for interacting