Originally, though, I suppose they were all hearts, clubs, spades & diamonds, weren't they?
Nope.
With playing cards, it depends on where the deck continued to "evolve" after playing cards were introduced to Europe. For decks with four suits:
-hearts/clubs/spades/diamonds are French suits.
-chalices/clubs/swords/coins are Latin (Spanish & Italian) suits.
-hearts/acorns/leaves/bells are German suits.
There are others:
http://en.wikipedia.org/wiki/Suit_(cards)
There are numerous examples of playing cards from the mid 16th century where the suits were lions, peacocks, monkeys, parrots, columbines, pinks (carnations) and roses...and the face cards were multicultural(!).
Cards didn't necessarily develop along one consistent line; they've always had different purposes and people have always come up with their own variations on those themes. Think of it as if you were cleaning out your junk drawer and came across a bunch of random cards: baseball cards, multiplication flashcards, playing cards, Bible verse cards, Pokemon cards, and cards from the Trivial Pursuit game, and then tried to make them all fit the same story line.
Speaking only for myself, if a person is going to design a deck and still call it a divinatory/esoteric tarot deck (as opposed to the contemporary French jeu de tarot decks, which are for playing tarot), I expect it to be something that easily connects to RWS. Not because RWS "invented" Tarot with a Big T--it's well established that tarot was several hundred years old when the members of the Golden Dawn became aware of it--but because RWS codifies what became the contemporary standard, wherein we have a system consisting of:
-22 major arcana
-56 minor arcana
-wands relate to the archetypal world, spirit, fire
-cups relate to the creative world, soul, water
-swords relate to the formative world, astral body, air
-pentacles relate to material world, material body, earth
I don't care if someone renames the suits as part of bringing their vision for the deck to fruition, if it's necessary and it fits. I think it's somewhat like deciding to invent a new alphabet and language before writing a book, though.
I don't expect new "tarot" decks to relate to Thoth and Etteilla. To my way of thinking, Thoth and Etteilla are their own thing, just like Lenormand decks and oracle decks are their own thing aren't marketed as "tarot" decks. If someone developed a deck which didn't conform to the contemporary 78 card tarot--extra suits, extra cards, significantly modify the associations, etc.--I'd expect that to be marketed as a new divinatory/esoteric system or an oracle deck.
I think tarot is both timeless and contemporary. If new decks with new, culturally relevant art--and with it, new card names--hadn't always been part of the mix, tarot would have become a stagnant relic of a bygone age. Instead, it's always shown the capacity to grow and change yet stay unchanged, remaining relevant to people in all eras.
I think some of the contemporary French jeu de tarot decks are cute, like the Droopy tarot.
That's just my well-considered newbie opinion, though. And we all know what they say about opinions--everybody's got one!
imarya