Twitter's new approach of third party application? How would you see this move as developer… especially you plan to build a twitter client

Question

Just today morning I have read news that twitter has issued a warning to developers not to make any new third party client, the official announcement can be read here.

As a programmer, how do you see this move of twitter? Does it seems that they want to standardize the behavior of third party client or they don't want any new client in favor of the default clients they have made?

What if anybody wants to create a new client? Is there any guidelines that-if followed- ensure that we can create a new mobile client? Or we should stop thinking about it? What are the option for the developers who want to build some clients for twitter?

I can realize that I have asked too many questions, but I still think that there can be one common answer.