JD_2020 has posted this on callofduty.com:

JD_2020 wrote
IN PROGRESS
Title Update 4 is nearing the end of Phase 2 testing. Going into Phase 3 submissions on 12/6.
Patching process: [ Register or Signin to view external links. ]

Patching Process

JD_2020 wrote
Hey Black Ops community

To answer many questions about the game update / patching process, Ive provided a short walkthrough below to explain how it works and provide some basic timelines for each phase in the cycle.

Phase 1: Gather feedback, reproduce reports and implement solutions.

As soon as the game is released, we scour the forums and play online with fans to gather feedback.
The QA team reproduces all feedback reports in a test environment, enters them into our database, and assigns them to dev team members.
o Like any scientific process, reports must be reproduced in the test lab before they can be addressed. With millions of users playing the game, something reported by only a small number of users may not be easily reproducible. For this, its important that all reports in the forums provide as much helpful information as they can.
Estimated time: Generally 2 weeks to build a comprehensive list, reproduce in the test environment, research cause, and implement solutions. This phase is typically the longest part of the process and can easily take more than 2 weeks, depending on the number and complexity of reports. Once a game is released, every change made is high risk, and adequate time is needed to implement the best possible solution.

Phase 2: Test internally.

Once the highest priority reports have been resolved, the updated game goes through a rigorous internal testing procedure.
If new issues are discovered or the original issue is not fixed appropriately, more time is needed to research and implement new solutions. Video games are highly complex pieces of software. Every change made has a potential impact somewhere else in the game, so the entire game has to be tested with each update.
Estimated time: Minimum of 1 week to thoroughly test the entire game and internally approve the update for release.

Phase 3: Console manufacturers test and approve the update for release.

As soon as our QA team has approved the update internally, it is then submitted to the console manufacturers for their own testing and approval. At this point, it is out of our hands.
If the game update is approved by the console manufacturers, the cycle is done and the update is prepped for release. If the game update is rejected, an accelerated version of the entire process starts again.
Estimated time: Minimum of 1 week to get an approval.
o Note: PC patches do not require manufacturer approvals, but because of the high number of variables in computer hardware and OS configurations, both Phase 1 and Phase 2 require additional time that does not exist on consoles which have standardized hardware. The PC patch development cycle takes about the same amount of time start-to-finish as that of consoles.

Phase 4: Release

Once the game update is approved by both internal QA and the console manufacturers, it gets prepped for release. This is a very short phase, but it can add time to the process depending on a number of variables.
Estimated time: Generally 2-3 days.

That is a high level overview of the patching / update process. Time estimates listed above are averages it usually takes at least a full month to complete a game update cycle. Often, there are multiple full game updates in the works simultaneously, which is why you see less than a month between full game updates. In some emergency cases, this time can be accelerated, but this is very rare.

The description above outlines the process for publishing permanent game updates and does not apply in the same way to hot fixes. Hot fixes are temporary, server-side fixes that are used to patch in simple adjustments to the game. These are not permanent fixes, and they only apply to online portions of the game. Most significant changes to the game cannot be made with a hot fix.

There you have it hopefully this removes some of the mystery of the game update and patching process. Enjoy the game and continue to communicate your feedback to us!

Regards,
-JD

I hope this information is helpful for some people.