I've discovered that this limitation is not a limitation, but a setting - and it can be altered! Go to Central Administration and then browse to:
- Application Management > Manage Web Application.
- In the Web Application list, select the web application you need.
- Then go to General Settings > Resource Throttling.
- In the Resource Throttling window, scroll down to List View Lookup Threshold and change the value to the number that suits your needs.
Of course, increasing this value degrades the performance, as there's more drilling through SQL tables, so be careful not to go too far. And one more thing: changing this value not only affects the list views, but it also changes the behavior of the methods that work with list items. E.g. having this option set to 8 will result in returning a maximum number of 8 lookup fields for a list item, when the GetListItems(query); method is called (Client Object Model). Increasing this number to, say 15, would consequently increase the maximum number of returned lookup fields for a list item. Pretty neat!