I had never did event blogging in past. So I don't have much experience of it. But I can give you some suggestions of upcoming events.
1. Micromax Yu Yureka smartphone -Micromax is going to launch another smartphone on 13 January. You can create website completely based on Micromax Yu Yureka. You can write about its specs, features, comparison with other smartphones, tips and tricks, Hands on review, unboxing etc.
2. Onda V919 Tablet -A dual boot Tablet which will be available in market in few days. There is very much hype about Ondo V919 due to its dual operating system support. You can write about it. It is a profitable niche.
3. Spartan Browser -A web browser which is revealed by Microsoft for its upcoming Windows 10 OS. You can write about its features, previews, specs, secrets, comparison with other browsers, how to guides etc.
4. Steam Machine -Also known as Steam Box. Steam Machine is a Gaming PC/Consoles which is not announced yet. It is in development stage by Steam (largest digital distribution network of pc games). It is combination of a Gaming Console and a Gaming PC. There are very less resources about it on the internet. This is a very profitable niche.