The Mobile Depot is small enough to fit into most ships’ cargoholds, and can be deployed quickly to enable EVE pilots to change their ship loadouts whilst still in the field, removing the need to operate out of a static station headquarters.
This is significant because a single ship with enough versatility – for example, the new Sisters of Eve Stratios cruiser - can feasibly be fit to stealthily travel to a location of choice and remain hidden whilst scanning down lucrative hidden anomalies. Once a suitable site is found, the ship can deploy a Mobile Depot to change its loadout using alternative modules carried in cargo, for optimal performance to exploit the anomaly (or to deal with the poor unfortunate who got there first).
In the grander scheme of things, this device will impact on EVE’s gameplay across a variety of playstyles. It will likely become standard procedure for organised fleets to change tactics on the fly, creating much more dynamic and unpredictable scenarios. That small gang you and you’re corp-mates are stalking after giving them a scare? They might be a different prospect the second time you meet.
Another factor to consider - the Mobile Depot is not hard to scan down. Players hiding in safe spots can be caught unawares as they tweak their fits, and players getting into the habit of carrying a depot and a stockpile of alternate modules will make kills more lucrative and losses more painful.
Whilst the Mobile Depot certainly doesn’t replace the more static service provided by starbases (also known as POS – player-owned structures), its introduction certainly suggests that the groundwork for modular starbases is being considered by CCP, which is certainly a positive step toward a less painful approach to player housing than the existing, convoluted starbase system.