[UPDATE] 7 July 2014: Updated to reflect the final confirmed list of 46 teams. Specifically, this involved confirmation of Japan and Singapore’s attendance, and the addition of Namibia. This puts the tournament at 46 teams and I suspect this will mean 6 groups of 6 along with 2 groups of 5 forming groups A-H respectively.
This is based on the 45 teams who have been named as either attending or pending by the organisers of WSDC 2014. Data is drawn from tabs of the last 17 WSDCs.
New Zealand return to the top of the table after last appearing in the top spot prior to WSDC 2010 with a clean record of 24 wins from the last 24 preliminary rounds. England maintain its spot in 2nd with Australia dropping to 3rd. See here for the 2013, 2012, 2011 and 2010 lists.
Since the use of a draw grid was introduced at WSDC 2010, the tournament has seen 48 or more teams, leading simply to sets of 6 with slight increases if necessary. It remains unclear how the grid will be structured this year with just 45 teams, and potentially might see 4 sets of 11 instead of 8 sets of 5/6 as the basis for the grid.
In any event, here is the unofficial list showing how teams have performed in the last few years and where they are likely to stand in the pre-tournament ranking process. This is the average performance of each country in the preliminary rounds of the last three tournaments. The pre-tournament ranking system was introduced at WSDC 2010 but this is no guarantee that WSDC 2014 will use this system. The order of countries is first by the average number of wins, then average number of judges. In the few cases where this is insufficient to distinguish teams, I have gone with the team that has a higher number of wins and judges at WSDC 2013. (Ireland>UAE, South Korea>Scotland, Thailand>Philippines, Slovenia>Lithuania)
WARNING: I am personally responsible for any errors and apologise in advanced for any. This list is not official and not certain of being 100% accurate, it is intended merely as a guide.