* Is the data searchable - can you filter by the criteria you require?
* Depth - do you get the level of detail you require, on all aspects of data that you require?
* Is data timely? and is it easy to find out *when* data should be released?
* Multi-lingual options of the site.
* Is data-downloadable in bulk format?
* Is data machine-readable?
What other considerations need to be taken into account when making government data openly available, in order for it to be as useful as possible to your organisation?