As already noted it is a strange thing to define outdates aspects in a SF RPG
Well, my try to get those three :
Mapping:
Traveller astrography is either outdated of just completely fictional.
iMHO there should be a consequent real space - Traveller Space mapping as well as the use of the actual astronomical data (coordinates, star types/configuration), similar to T2300 or Mals approach. This would encourage the "living in a real universe" aspect and stress, that the typical Traveller 2D maps are just jump space navigation aids.
I did that for the Marches, too, using old and new versions of Astrosynthesis or even Celestia as display machines.
Its pretty cool to show players a real star map and say "Here, this one, No. 17993 from the Hipparcos catalogue, located at -89,37/-170,28/-237,78, is Rhylanor systems main star".
Discreet design numbers:
Guess thats more mechanic, but somehow it shaped the impression which Traveller creates on players.
I really dont like the rounded 1 to 6 stat values for manuever or jump drives and the absolute limit of 6. This has to much "must fit to 1D6 scheme" taste.
It would not hurt anything, if the design sequence could produce real numbers here and if the upper borderline is perhaps a "economical" boderline for TL of 15, but improvable at higher TL.
Aliens:
Personally I have many problems with any kind of alien, which is some kind of modified Terran creature (let it move upright and put it in a suit...huuuaaa). Well, OTOH the existence of most of these races, could be "explained" with the ancients.
Anyway, I would be really intrestet in a scientific rework of our dear Aslan or Vargr friends. Also I definitly would radiacally reduce the number of those "races from the zoo" geneered to intelligence.
IMHO any unconvincing race turns Traveller into a muppets show....
Honstely I see no other aspects really to be classified "outdated".
Many "modern" or "hype" aspects like nanities, cyberstuff etc, are just not especially noted in Traveller, but surely not excluded.
Regarding the computer topic I would just advise people to have a look at sites like
http://www.top500.org/lists/2005/11/basic and click a bit thru, in order to get an impression how big computers can become
Regards,
Mert