Okay, bad pun in the title. But I've finally made it to Dalaran and thought I'd share ways in.
The One That Doesn't Work
There's a floaty run in the Crystal Song forest. Clicking on it (it gives you the gear icon) takes you up to Dalaran. Except, this won't work unless and until you've used the rune that's already inside Dalaran.
The Easy One
Just level. Once you hit 74, a Kirin Tor mage in one of the quest towns will have a quest open to you. You'll get an easy port to the city with a quest to activate the run inside so you'll be able to head up from Crystal Song Forest (see above).
The Cheaty Way
If you have someone in your guild (or friend's list) that is already in Dalaran, have them invite you to a party and queue for a battleground. Once you're in, /afk from the BG. *bam* You're in Dalaran.
So, now that you're here, what can you do. Well, just about everything. There are at least two inns (one for each faction) with portals to all the old cities including Shattrath. Additionally, there are portals to all five of the battlegrounds (including the new Strand of the Ancients). There are also profession trainers for every profession. There are places to fish (try the fountain), places to buy new mounts, places to trade in the "new" badges of justice for gear. And there are profession dailies. Oh Lord are there. My hunter is trying to do both the cooking and jewelcrafting daily each day. The really nice thing about these (over the ones for fishing and cooking in and around Shattrath) are that the rewards are non-random. You get a token (it appears on your currency tab of the character sheet). Once you have saved enough tokens you can buy exactly the recipe you want. In time, I suspect, I'll get them all. But it's going to be very nice to be able to cook the food my hunter wants to eat for dungeons instead of relying on my guild. Same with the gems--I can buy the Agility/Haste/Attack Power gems first and fill in the holes later on.
I've only two characters who've made it to Shattrath so I'm not sure how recipes are acquired for other professions. It appears that cooking and jewelcrafting work as above. Enchanting seems to allow you to trade enchanting materials (shards) for recipes. And tailoring looks like you just buy stuff the old fashioned way. I cannot speak for engineering, leatherworking, blacksmithing or inscription yet. But I do know the Heavy Frostweave Bandage is a drop from instances.
Back to the leveling, I guess. Have fun out there.