If we are talking about their Orange Savings account...it's pretty good for an FDIC insured product. The underlying products are probably CDs which offer a pretty good rate for what is essentially a money market account.
Now if you were to upgrade to their investment account you would hold mutual funds which fortunately look like they are no loads so you aren't paying any up front sales charges (which is good)...but there are annual fees that mutual funds carry, so it isn't "free". Also as mutual funds invest in stocks & bonds there returns can never be guaranteed and there is always the potential to lose money.
Still, I say if you are comfortable with the idea of a savings account at a bank I would certainly say the risk of an Orange Savings account are about the same. ie: you are covered by FDIC if a catastrophe happens.
ING is also a huge multi-national corporation that isn't likely to go anywhere...so I say go for it.