The government of India, in 2008 gave the go ahead to ISRO in it's effort to develop an indigenous Semi-cryogenic engine that would power the core stages of future Indian launch vehicles. The project has been one of the priorities of ISRO and it plans to complete the development phase of the project by 2012.
The design specifications call for an engine delivering about 2 MN (2000 kN) of thrust at sea-level, fueled by Kerosene and Liquid Oxygen using a high pressure staged combustion cycle.
Keeping aside the criticism faced by ISRO for being late by about 25 years in developing this technology, this project really takes ISRO and Indian space capabilities to a new level.
This engine in the long-term will power our future UMLV family and probably the first Indian moon rockets (so called Superheavy launch vehicles), but it does offer interesting possibilities in the shorter term.
ISRO plans to replace the core stage of GSLV-Mk III with a more powerful one powered by this engine. Of course, GSLV-Mk III is yet to fly with it's present configuration but that doesn't mean that ISRO should stop working on future upgrade plans. The present L110 stage of Mk-III is powered by a cluster of 2 Vikas engines powered by Hypergolics. It will enable the Mk-III to put satllites weighing around 4-5 tons into GTO and about 10-12 tons to LEO.
The new core stage could be followed with other upgrades such as an expander cycle upper-stage engines replacing the current gas-generator ones which would allow multiple restarts of the upper stage, hence making the rocket more efficient.
The new core stage will be powered by a single, possibly ground-ignited Semi cryogenic engine with the propellant mass being similar to the present 110 tons. This change will increase the capability of Mk-III to about 6 tons to GTO and about 15 tons to LEO. Upperstage upgrades could further increase the GTO performance.
The timeline of these upgrades would depend on timeline of development of SCE and the GSLV Mk-III program. By current estimates this will happen no sooner than 2015 possibly even later. But testing these new technologies on GSLV-Mk III could act as a testing ground for the future UMLV family which could cut-short it's development time.