Hi Skullshaper, no, still here. 
As for ideas, they might be simmilar, but to be frank I never heard of that game. But hey, I just started by thinking what would make a cool addition to Sins...
*edit*
As for vanilla races, no, they won't be seeing Titans added to them. I plan the mod as an unofficial expansion, but with a twist - when it comes to strategy games I like diversity, both in unit types and gameplay. SoaSE follows a more traditional "mirror" style, where each faction has basically the same types of units and the same way of using them, with minor differences in stats, production costs etc.
The Xin are an invading force. An utterly alien one at that. They won't have access to some units or buildings the vanilla races have, and will have some unique units/structures of their own.
For example they won't have culture or media centers to spread their "culture" around. When they want to spread around, they do it with lots of booms and bangs, not talking (not to mention that aside from the Consuls, apparently no one has managed to decipher their language... instead they will have a special "black market depot" where the unsavory traitors from local races can exchange all kinds of goods with them. Since the Xin won't be able to generate credits natively (but won't need them for much else than black market trading and paying off pirates), the depot will basically serve as a resource/money converter, a sort of an additional way for the Xin to balance their resources. Since the conversion rates are fixed, a potentially very powerful structure in the hands of a more subtle-minded Xin commander.
And so on. The differences may in some cases be subtle, in some cases not, but the overall goal is to make you feel like you're playing with or against a unique race, not a copy/paste one with different graphics and few math tweaks.
