Blizzard will be implementing a fix some time in the near future that will 'throttle' inspection of other players. This is being done ostensibly to reduce lag and server load; some addons, notably ones like gearscore rely on gathering information about the equipment of players around you to create easily understood values for their gear.

From WoWAce.com:

I've received word that after the next set of rolling restarts, which may be happening as early as tonight, inspection requests on other players will start to be throttled.

This is being done because some addons generate a large number of inspection requests, so beware as some addons may start to behave unexpectedly, flat out break, or otherwise act up. Overall I hope it not to be too bad, but you never know, so here's the heads up.

Addon authors may need to restructure their addon so that they may _never_ receive a response back from a request. We may be seeing several second long intervals between allowed requests, and as I said, some request will likely never be answered.

If I hear any more details I'll update the post.

This will not break the gearscore addon or other similar addons according to modding experts but may slow them down somewhat. When asked whether this change was a direct assault on the gearscore phenomenon Blizzard had this to say:

Nethaera (Link)

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It's important to understand that the throttling that is being done isn’t intended to break any functionality of add-ons, but merely to control the amount of queries that are being sent to the server at any given time. (Thus throttling the queries.) The queries will still occur, it just won’t happen as quickly as they currently seem to. You can read the statements that WoW Ace and WoW Interface have up for a bit more information on these changes. We wanted to give mod authors a heads-up prior to making the change so that they could make any adjustments they needed to on their mods.

http://wowinterface.com/forums/showthread.php?t=33432
http://www.wowace.com/announcements/blizzard-to-start-throttling-inspect-requests/

Gearscore is a highly controversial addon and there is a vocal group of players that wishes for the addon to be broken, so it's worth watching whether or not Blizzard implements additional measures to curb its use.