Telehubs were created with the release of Version 1.1.0 as an alternative to pay-to-direct teleportation. Linden-owned, these properties and builds created a network in which a resident would teleport to the closest telehub to their desired destination. Another intended use for the telehubs was as a social structure and meeting area, but residents rarely seemed to stick around. A side benefit Linden Lab had hoped would be that telehubs would help in "urban development", creating more commercial centers around them, and leaving the outskirts of land further away from the "hubs" for residential-type land. The telehubs also provided free content often created by Lindens, ads placed by residents, and a map of the resident's current location in the world (these maps were often left out-dated). The world map in SL's UI was later updated to include helpful information on telehubs, such as location and coverage of which telehub the resident would end up on depending on where they wish to go.
Ryan Linden wrote the original design documentation for the telehubs, at first calling them "perches" with the idea that they would all be in the air (like the Oak Grove and Mauve telehubs pictured below). However, due to residents sometimes falling off of them, a land design was favored soon after introduction. The original design and art was done by Eric Linden and Alberto Linden and the name "telehub" was a derivative from a term Phoenix Linden used in referring to them as "telehubbies". One idea that was considered during conception was that residents would have to go to the telehubs to recieve their stipend but this idea was dropped and never implemented.
The removal of the ability to directly teleport being built into SL itself, and the limitation of being required to use telehubs, lead to a new business type of resident-made objects that would quickly take you to a location at extremely high speed. The most popular of these was/is a service called ROAM, created by Francis Chung and Rathe Underthorn, which allowed a resident to travel from a specific location or sim at super speed (among other things). There were some other alternatives to ROAM such as Hank Ramos' free service of similar features to ROAM and also several flight scripts that enhanced the resident's speed. These objects served residents' needs to get to places faster than telehubs allowed them and, sometimes, such as when teleporting was broken, with more convienence. The downside of these types of services was that they still required the resident to cross sim borders which could sometimes fail or, on poor connections, not be so smooth.
With SL 1.8, LL decided to remove most telehubs and only leave them for private sim owners who wish to still use them. In replacement, LL has brought back direct teleportation - this time without any fees. Where the telehubs were previously located, new infohubs built by Ben Linden were put in as temporary replacements until resident builds (won via bid) were created as permanent landmarks. The infohubs were created with two things in mind: to easily distribute information to residents, and to create congregation/meeting areas. Also, LL is hoping the infohubs will create traffic around the area so that those land owners around them will still remain rather popular.
The reason for the removal given by LL was that new residents became confused when for example attempting to go to a store but ending up at a telehub instead, and the map beacon showing where to go was either not visible or not user-friendly enough to work with. There are several other reasons residents believe that telehubs were taken out. A lot of those reasons being based on the content around telehubs, that of clubs or malls, which often contain alot of prims, slowing down the client and cause "lag". Also they felt that telehubs were in large part a nuisance, causing frustration when needing to get somewhere fast, which also mimicks the frustration new residents had with them.
However, many residents who rent and sell land were angry at the decision to remove telehubs because telehub land provided high land value due to dwell/traffic and actual viewership traffic. LL argues that this change in the long term may actualy bring a rise in profit for these same residents.