Not that I've watched much IPL over the years but I think the last few I've seen have more and more home based players and less overseas? Lots of older 'stars' just there for the cash. Not that I know about the standard but I doubt the IPL is that good compared to others.
I've watched every year. The standard in terms of other t20 competitions is certainly the highest.
Indians seems to take to this game well, so there is a lot of home grown stars, but every team always fills there quota of foreign players allowed in the side(I believe it's 4 out of the eleven currently)
And they are often having to rotate them as they have 6-7 foreigners in each squad.
Off the top of my head
WI- gayle, bravos, Samuels, Sammy, roach, smith
SA- kallis, steyn, morkels, duminy, petersen, de villiers, dunplesis
Aus- Faulkner, Johnston, hogde, Watson, Warner, maxwell, finch, henriques, husseys, smith
Sri Lanka- sangakarra, dilshan, kulsakerra, jaywardene, Malinga,
New Zealand- Taylor, mcullum, vettori, Rutherford
That's just off top of my head, and there's some definate world stars in there, along with a few at the end of there carreers, but can Definately cut it at t20 still.