Current class distribution?
And what do you mean by class distribution? Do you mean how many ppl play each profession?
I play all of them and imagine that’s fairly standard. Or at a minimum, five professions if one hasn’t added any character slots.
How would we know what the distribution is?
Play what you enjoy.
As far as something like a census goes I don’t believe that’s possible, so one would be making an educated guess at best.
TL;DR: Every class in GW2 can be played in a wide variety of set-ups. Overtime certain set-ups (and classes that do them well / sync well together) have formed a so-called ‘meta’ which is similar to other games fotm expression, however, it’s not just the class that makes you meta (closest thing to favour of the month) it’s the builds (traits/gear/weapons etc.) For example a non-meta Guardian would be less ‘optimized’ than a meta-build Engineer, despite Guardian being a more common meta-class. For this reason I highly recommend to pick a class which mechanics you think you’ll enjoy, you can always trait them to be the ‘underdog’ if that’s what you’d like.
However to answer your question:
PvE meta is mainly dominated by Guardian, Warrior, Thief and 2x Elementalist (though Mesmer isn’t uncommon in highly organized groups instead of a Guardian.)
- Guardian / Mesmer for Reflects, Condition Removal, Stability, Aegis (Guardian) and Timewrap/Portal (Mesmer)
- Warrior for Banners, potentially for Might-stacking.
- Elementalist for permanent Fury, Might-stacking, burst Vulnerability and one of the highest DPS available and Frostbow (5s stun + high AoE dps.)
- Thief for smoke-fields (group-stealth) blinds and high personal dps.
For WvW a similar mixture of classes are generally preferred;
- Guardian for Stability.
- Warrior for heavy CC.
- Elementalist for some CC, Fire/Waterfields.
- Necromancer for high AoE dps (Wells + survivability from Death Shroud to allow more offensive stats) with boonstripping.
sPvP is mainly dominated by Celestial users (Engineer, Warrior, Elementalist) but it’s more of a Rock/Paper/Scissor game of builds countering each other.