Hi Stefan,
can you explain what you understand by 'SAPUI5 development'? In fact the eclipse update site you mentioned is the one I named hana tools update site. If you point eclipse to this location you'll be able to install tooling for creating web applications with sapui5 interfaces. Note that you can also write applications which don't include the sapui5 runtime but use the runtime deployed at the hana cloud (https://sapui5.netweaver.ondemand.com/sdk/) and define some local resources (see https://sapui5.hana.ondemand.com/sdk/#docs/guide/ModularizationConcept.html).
Best regards,
Tobias
