4th Edition has new treasure rules.
The days of rolling up random treasure hoards are over; under the new regime the words "Treasure Type S" are gibberish. 4th Edition uses treasure parcels.
The treasure parcel system described on pages 125 and 126 of the Dungeon Master's Guide turns assigning level-appropriate loot into simple maths. You break your entire campaign down into chunks of ten encounters. Every ten-encounter chunk has ten associated treasure parcels. Treasure parcels range from a level-plus-four magic item at the top end down to a measly handful of gold at the bottom end. The parcels might get handed out one after each encounter, or they might bunch up with none in one encounter and two in the next, but presuming players are at least industrious enough to search the room after each encounter they'll walk away with a predictable amount of treasure after completing all ten challenges.
The magic number of "ten" in relation to treasure parcels isn't random; that's how many encounters it's expected to take characters to level up in 4th Edition. A standard level-appropriate encounter gives out one-tenth the XP necessary for a five-man party to gain a level.
A ten-encounter treasure parcel spread for five players contains four magic items, and exactly enough cash to buy two more, providing they're level-appropriate. That has a couple of implications. First, a character can expect to gain roughly one new non-consumable magic item per level. Secondly, because items become obsolete within (roughly) five levels, players should expect at any time to be wearing no more than five or six items of level-appropriate gear. That's an issue, because there's nine equippable item slots.
Luckily, some items never go out of style. Acrobat boots, which let you stand from prone as a minor action, become available at level 2 and are thoroughly useful all the way to level 30. Gauntlets of the ram are the best hand-slot item for a character focused on forced movement from level 8 all the way to endgame (on a Malediction Invoker their property can trigger as often as four times a turn); for everyone else, the (deeply broken) antipathy gloves are ridiculously good.
These non-scaling powers are a bit depressing. Once a character gets a solid pair of boots that won't become obsolete they can afford to snub their nose at anything else for that slot that comes along, selling it for cash and buying the latest edition of their weapon-of-choice instead.
How then, does Thunderspire Labyrinth treat the treasure parcel system? Simply put, it ignores it.
Possibly treasure parcels came late in the 4E development cycle; possibly the authors never got the memo. Thunderspire gives out loot exactly as often as it feels like it, which is roughly never, and takes a perverse pleasure in ensuring that sums of cash are never divisible by five. While it's not quite as bad as Pyramid of Shadows (which seems to contain nothing but Wizard loot), the treasure in Thunderspire Labyrinth also suffers from being overly specific. There's nothing like telling your players they've found a +3 item, watching their faces light up, and then adding that it's a weapon that none of them wields.