We've noticed in our Twitter stream and from interacting with developers that there have been quite a few delays with Windows Phone Marketplace submissions. Before, it would take around 72 hours from submission to approval to publishing of the app. Now, it's taking significantly longer and there have been a few hiccups along the way too (see Rowi's recent update woes).
In the latest Windows Phone Developer Newsletter (April 2012), Microsoft confirms that indeed "due to high submission and update volumes, the app certification process is continuing to take longer than it has previously." Just how long? Microsoft states it can now take up to seven days which is quite an increase from the previous 72 hours. In turn, Microsoft is recommending to developers to plan accordingly by submitting as early as possible if they want a certain publishing date.
Of course this is a good news/bad news situation. It's a bit frustrating to developers who now have to wait significantly longer than it did a few months ago to get their app or app update to market. On the other hand, these delays are caused by a nice problem: a huge increase in app submissions to the Windows Phone Marketplace.
For point of reference, nearly 340 new apps are being published daily in addition to over 400 app updates which has resulted in just over 70,000 apps being available in the Marketplace (the 80,000 number is a bit misleading since it aggregates worldwide and doesn't count removed or inactive apps).
We imagine that if the Nokia Lumia 900 is successful, new app submissions could also increase over the next few months -- an issue we'll return to soon enough. Finally, Microsoft probably won't let this delay get any longer as they are trying to scale appropriately to meet the demand.
Marketplace statistics provided by WP7AppList