Right from when they were first implemented with the launch of City of Villains, bases in CoX have always seemed half-done. The initial design for the base raiding system - such a key aspect of CoV that it was the basis for the trailer - involved characters going off to steal an Item of Power from Rularuu, after which they would have to schedule times when the base would be vulnerable to raiding. Incoming teams would try to steal the Item of Power, and the defenders would have to protect it, for no reward other than holding on to for another day.
On paper, this must have looked fantastic. In practice, it didn't pan out. The cost of rooms that could take base defenses, such as the interesting-looking turrets, was prohibitive. The Cathedral of Pain trial, which was the intended source for the Items of Power, passed through several iterations before finally going live, only to be withdrawn again when a fatal bug forced it. The bug allowed constant XP gain for repeated mouse clicking, so it couldn't be allowed to stay in.
Base raids were riddled with faults, too. The victory conditions often come up for criticism. For example, one method of victory involves planting Disruptor Pylons in multiple rooms. As the only way to prevent this is to check each room constantly, the more rooms you have, the easier you become to defeat by this method. This means roleplayers or dedicated architects who want to build sprawling complexes are vulnerable, while hardcore PvPers restrict themselves to as few rooms as possible.
'Scheduled' raids, where players try to steal each other's Items of Power for real, have never so much as taken place; the code has never made it to the live servers in a workable form. 'Instant' base raids, where there are no consequences for victory or defeat, have proved far more successful and are one aspect of the system that sees regular use. Even these, however, are problematic. Unintended use of base scenery has meant that raiders can be teleported into ad hoc wooden prisons or otherwise hindered. It seems doubtful that these tactics will continue into Issue 13, as a thorough list of 'abusive bases' is already being compiled for the Devs.
Despite its failings, the base design system in CoX still has many enthusiastic users who take justified pride in their architectural accomplishments. The limitations of the system have become a spur for creativity, as base designers use objects in unintended ways to create spectacular effects. The best example is the Magic Desk, which uses a stacking property to suspend objects in midair.
The base-building community's reaction to Matt's comment has mostly been welcome and relief. Some remain cynical, however, pointing out how long they've been waiting for something to happen with bases. The former Lord Recluse, Serdar Copur, first mentioned that 'both Supergroups and Bases will be getting some much needed love over the next few updates' as long ago as April '07.
For our part, we can't wait to see bases become all they can be. The Surviving 15 now have the backup they need to make this happen, and Matt has specifically mentioned base revamping as one of the goals of the expanded Dev team. We've already seen what may be an unintended sneak preview of the revamped base system in the Beta of Issue 12, when a build accidentally revealed tiny decorative rooms called 'apartments' which cost no Prestige. Rularuu has also been mentioned again, raising hopes that the Cathedral of Pain Trial (or some suitable replacement) may finally be arriving.
Raid-style endgame content for large groups of players that enables mass PvP on a player-built map? It could happen, and it could be just what CoX needs.