Rudiantara, Indonesia's ICT Ministry (Menkominfo) always said that there are too many cellular operators in the country. He also look for ways to shrink this number to four, even three.
When the government is arranging the network for 1800MHz 4G LTE, they placed Indosat's band next to Tri's band. This is a clear sign that there is an intention to merge the two companies.
Remember when XL and Axis are put next to each other on 3G band? See what happened now.
If it did happened, on 1800MHz band that have 2x75MHz wide, Telkomsel and XL already have 22,5MHz each. And Indosat will have 30MHz (20MHz Indosat + 10MHz Tri).
What it mean to us? The bigger spectrum one operator have, the bigger bandwidth they can provide to their end users, the faster the Internet speed we will get. So, this is good.