The Wrath of the Lich King has greatly increased the amount of high-quality items available to players who don't have a lot of time to spend (sometimes called casuals). This page consists of a overview of methods to obtain them.
Most WotLK factions offer various epic rewards when your reputation reaches exalted. All factions have at least one armor piece which is considered very good for the classes it is intended for.
The first dungeon ran using the Dungeon Finder will reward two Emblems of Triumph. In addition, Trial of the Champion, Forge of Souls, Pit of Saron and Halls of Reflection all drop epics on normal difficulty.
The final bosses of heroic dungeons will always drop an epic item, as well as a Frozen Orb which can be used for crafting various epic pieces. In addition, all heroic bosses will drop an Emblem of Triumph, lootable by everyone in the group, which can be turned in, in varying amounts, for additional rewards.
There are also some Bind on Pickup craftables; these require a high skill in a crafting profession in order to craft and must be crafted by yourself. Most of these are trainable, but additional high level patterns (which are themselves not BoP and can be bought) are available in raid instances. These are typically considered extremely good items, focusing mainly on stats deemed important by players. There are fewer of these on WotLK than there were on BC.
Bind on Equip Raid dropsEdit
Most raids drop a few items that are Bind on Equip, and these are sometimes sold in the Auction House. They tend to be quite frighteningly expensive, though.
Single Boss RaidsEdit
If you have some good connections, or just plain luck, you might get into a Malygos raid with a guild that knows of it, with some of the best gear, and only taking you less than an hour per week. This one is harder to do as casual, since the gear requirements are usually above what a casual can provide.
Both normal and heroic modes of Naxxramas can be done by causal guilds if they spread the clearing over several nights. Some fights are difficult to learn and require some good gear of all raiders, but in a few weeks the bosses will take several less tries and so you, as casual, can hope to clear it in 3 days max in a few weeks training.
There are several new PvP items in the WotLK
Wintergrasp Rewards Titan-forged Items