Not really.
The PS3 came out in 2006, it's now 2009.
Seeing as the PS1, 2, and 3 each came out about 6 years apart, we're probably about half way to the date when the PS4 will be released.
The PS4 is likely already under development.
Wat.
My friend, the PS3 is going to be here for a LONG TIME. It's only been about 2 years in total since it came out, why in words would they start developing a new console, if you ask me, if they were developing it now, it wouldn't have all these improvements, and it won't have better graphics than the PS3, hell no. And if you believe PS4 is in development, prove it, from a trusted source. I don't think so.
Likely:
# has a good chance of being the case or of coming about; "these services are likely to be available to us all before long"; "she is likely to ...
# probable: likely but not certain to be or become true or real; "a likely result"; "he foresaw a probable loss"
# expected to become or be; in prospect; "potential clients"
# probably: with considerable certainty; without much doubt; "He is probably out of the country"; "in all likelihood we are headed for war"
# within the realm of credibility; "not a very likely excuse"