Is there anything worth saving for Cata?

[Kamandra]

Sounds to me like for, i.e., Inscription, glyphs are going to go in the dumper pretty fast come cata. Who wants to spend all their time standing in from of the AH competing with gold farmer bots undercutting your glyph posts every few seconds as soon as the expansion comes out anyway?

Herbs will all be new ones so guess I should dump any and all of the northrend herbs since nobody's gonna want them when the new ones come available. Can't hardly give them away at this stage because alot of peeps have quit playing waiting for the cata release. Flasks and pots are selling at an all time low too. Frost Lotus will become like the fel lotus and black lotus selling for 1g-2g ea. too I'm assuming. The BC and classic herbs only sell now for inscriptionists to mill, see paragraph above for how even more useless those will be.

I'm sure all the WotLK ore, leather, cloth, etc. will be completely useless except to those who might want to level a profession, although if everyone is pushing jewelcrafting and blacksmithing as the only viable professions for cata...well you can see where I'm going with this, all those in the dumper too.

The concensus seems to be that everything we have in our inventories right now is crapola, auction house not viable because of low demand so I'm thinking it's ...vendor time. Agreed?

[killzwitch]

You would be suprised how much money I make from selling ores around the Mithril/Thorium mark - many people need the gems from them and many BS need the smelting skill (mining). I tend to find all BC stuff sells for pickles - and so when WOTLK is the previous expansion the same will be said of that stuff and perhaps tbc bits and bobs will become more worthy, my advice is to sell sell sell now and then sleep.

[Imnick]

Hold onto your northrend herbs, in 1 or 2 patches time nobody will want to farm them and you can get rich of people levelling alchemy and inscription from the AH.

[Aley]

I'd expect quite some demand for Mechano-Hogs/ Mekgineer's Choppers during Cata, as quite a few people (myself included) would love those awesome mounts for their new Worgen / Goblin alts. I expect the mats to raise in price as a less people will be farming the mats, such as Titansteel and Arctic Fur.
In addition to this i expect glyph prices to raise dramatically, as the herb prices for both Northrend and Cata herbs will be a lot higher. The demand, however, will dramatically increase for the first few months as everyone wants to get all the glyphs available ASAP.
Another profitable market might be flasks / potions, depending on the lvling rate of your fellow Alchemists on your realm: The hardcore server-first players might be using an awful lot of flasks and potentially potions too.

It'd be pretty useless to stack onto most Northrend mats if you want to make a quick profit, though there might still be a steady demand from profession lvlers over time. The only really long-time desirable mats might be the high-end ones for "special" items, such as the Chopper and maybe Jeeves. Do not estimate the power of alts, however, as some might be going to level crafting professions and/or secondary professions en masse.

Regarding your statement of scribes buying vanilla / BC mats, this is usually only true for people rolling a scribe on a completely different realm, as buying Northrend herbs, asking a guildie to make them into Icy ink and trading those for the low-lvl inks is usually cheaper. (During my Insr. lvling i sometimes had to buy vanilla herbs for 50g+ / stack, while Northrend herbs were around 15g / stack.)
So yes, try to sell your herb stock to a scribe / alchemist stocking up for powerlvling, as the demand will drastically drop during Cata. Try to AH your old mats before vendoring, there might still be some idiots out there who haven't heard of Cataclysm yet.