With the release of Wrath of the Lich King approaching, we wanted to
provide you with some important information. In preparation for the
expansion, we will be issuing a new content patch in the coming weeks.
Much like the patch made available shortly before The Burning Crusade's
release, this content patch is designed to bridge current game content
with that of the expansion and will contain some exciting changes and
additions.

We have outlined some of the larger features scheduled to release with the patch below:

New class spells and talents
Stormwind Harbor
Barbershops in capital cities
Zeppelin towers outside of Orgrimmar and Tirisfal Glades
Two brand-new Arenas featuring challenging new layouts, terrain hazards, and moving obstacles
Guild calendar
Hunter pet skill revamp
New profession: Inscription

As
mentioned above, this is not a comprehensive list, just some of the
major highlights. We’ll post the full patch notes as soon as they’re
available. Regarding Inscription, please note that all Burning Crusade
players will be able to select Inscription as one of their two
professions and level up to a skill level of 375 with it. Upon the
release of Wrath of the Lich King, players who purchase and install the
expansion will be able to continue leveling in Inscription and the
other professions beyond 375.

If one buys a new account and upgrades it to WotLK, does one also get BC content?

Ill have to look into that, right now I'd say no