What ICANN did on 26 June 2008 was to give a green light for many more generic Top Level Domains (gTLDs) to be created, essentially without limit, but there is still a long and winding route ahead.
However, we are not really talking about a change in policy; this is rather a realisation of the inevitable. New gTLDs have previously been established since the "original seven" of .COM, .NET, .ORG, .GOV, .INT, .MIL and .EDU created in the 1980s. In November 2000 seven new gTLDs were selected: .INFO, .BIZ, .NAME, .PRO, .AERO, .COOP and .MUSEUM. In 2003 a further seven were selected by ICANN: .TRAVEL, .JOBS, .POST, .CAT, .MOBI, .TEL and .ASIA. To date we have 21 gTLDs, but very few people are aware of them all. The next enlarged round will thus be during the course of 2009.

A very good question and one that goes to the heart of the discussions over the last decade. On the one hand, many parties say that it is like real estate, and at present, there is a lack of such virtual real estate out there; hence, more gTLDs are needed to meet the ever-growing demand of internet users. In addition, specific communities of internet users wish to create dedicated gTLDs to serve their communities, one example is .BERLIN. The aim is to encourage and foster creativity, innovation, consumer choice, and competition in the domain name space. On the other hand, some would say there is no such need and argue that many of the registrants in the previously launched gTLDs were not new to the market. My view is that any new gTLD needs to add some value, if it does then there will be demand for it, if it does not then it will fail or fade away.
A new raft of gTLDs, in particular, concerns brand owners, and the possibilities these offer to cybersquatters and some domainers who will seek to divert traffic and make money on the back of well-known marks. The cost of defensive registrations to prevent bad faith use by others is ever increasing.

Brand owners need to firstly watch the new gTLD application procedures to ensure that no potential application might potentially infringe their brand - or prevent them subsequently applying for their brand as a TLD at a later date. If need be they should make appropriate objections.
As new gTLDs are introduced brand owners need to be aware of the sunrise period and understand how it works. It is unlikely that there will be a standard sunrise process for each new gTLD. Many brand owners fell foul of the validation process during the sunrise period at the launch of .EU for example, as either they or their registrars did not fully understand intricacies of it.
In order to participate in the sunrise periods, brand owners need to ensure that their relevant IP rights are protected in order to be able to take advantage of these periods. It is also worth underlining that we can expect the creation of new gTLDs comprising non-Latin script, for example Chinese, Japanese, Korean and Arabic scripts. Thus, companies should consider securing their key brands in as trade mark registrations in the appropriate country and local language scripts. This will stand them in good stead for not only the sunrise periods but also possible later UDRP complaints.
As ever one needs to find the right blend of defensive registrations, portfolio management, domain name watching and recovery. Finding the right balance is not easy though and one should also not forget the existing 249 ccTLDs (country code Top Level Domains).