>Strangely, instead of telling where to download the package, it says that the author is using an internal SAP download URL which does not work from the outside, customers are referred to the online help and to the Developer Guide which allegedly contains the download URL
Unfortunately there isn't a single location where everyone can download SAPUI5. Therefore in the video we must be intentionally vague. For customers who have an on premise HANA license, they can download the SAPUI5 tools from the service marketplace as described in the SAP HANA Developers' Guide.
For those using HANA One or the Developer Edition of SAP HANA, I do believe that you can use the trail version of SAPUI5 which is available for download from the SAP Developer Center here on SCN:
http://scn.sap.com/community/developer-center/front-end
>Other blogs here say that the AWS Hana should use Import/Delivery Unit to download the package from the server.
The Delivery Unit can only contain the server side components for SAPUI5. It does nothing to update or change your SAP HANA Studio installation.
Please note that the SAPUI5 tools within HANA Studio or Eclipse are not required for doing SAPUI5 development. They do contain helpful wizards and code completion; however the entire development process can be done with basic text, html, and JavaScript editors already available in HANA Studio. The complete SDK (Documentation) is contained on the server side and can be used once you install the Delivery Unit.