Google will update developer distribution agreement for the Play Store today, and two significant changes are in store. First, developers of paid apps will now be required to respond to users contacting them within 3 days of receipt of the email. How strictly Google plans on enforcing this is unclear, but it's likely the ominous Google Play ban-hammer will be a motivating (read: intimidating) factor for developers here.
For paid Products or in-app transactions, you must respond to customer support inquiries within three (3) business days, and within 24 hours to any support or Product concerns stated to be urgent by Google. Failure to provide adequate information or support for your Products may result in low Product ratings, less prominent product exposure, low sales, billing disputes, or removal from the Store.
It's worth noting that a response is not defined in this new clause, but presumably even a generic acknowledgement that the issue has been seen would be sufficient for this timeliness requirement. Failing to resolve support issues or respond in any way to support requests is what Google is probably targeting here more than timeliness, the 3-day rule would seem to be a bar arbitrarily set so Google can concretely say when it's justified in taking action.
The second change is a decided positive for developers, as Google will now handle VAT for all EU purchases. Previously, Google had required developers to handle VAT for their customers in EU nations - which is what is referred to in the technical parlance as "a pain in the ass." Starting on the 1st of January 2015, Google will take over the VAT situation for all EU transactions, including determining, charging, and remitting the tax.
Where Google, the Payment Processor or the Authorized Carrier is required by applicable (local) legislation to determine, apply and pay the applicable tax rate, Google, the Payment Processor or the Authorized Carrier (and not Developer) will be responsible for applying and collecting and remitting the taxes to the appropriate taxing authority. If Google collects and remits value added taxes on customer payments (where required of Google by applicable local law) and this remittance fulfils the applicable requirements for value added taxes on those customer payments, such taxes will not be passed on to Developer by Google. Where Google is required to collect and remit taxes as described in this section, Developer and Google will recognise a supply from Developer to Google for tax purposes, and developer will comply with the relevant tax obligations arising from this additional supply.
There's another smaller change to the DDA, too, but it just has to do with how Google communicates policy updates and other announcements to developers and promotes apps on the Play Store across various mediums.