Well, what have you done for me lately, right? Investors, less than thrilled with the returns that venture capital funds have been delivering, are taking their money and going home. The number of new funds launching has thus dropped precipitously, and it looks like the industry will be smaller, with fewer players, according to the National Venture Capital Association.

Of course, the next wave will attract many to ride it, and that could be enough to turn the tide (once again).

Private equity investors are using current financial market constraints on liquidity to negotiate favorable deals, as private equity general partners have watched the values of their portfolios fall profoundly. Efforts to attract additional investment haven't been easy, as potential limited partners are reluctant to make long commitments in an uncertain marketplace. This has given limited partners a stronger position from which to negotiate both fees and terms and conditions.

Limited partners are getting a leg up on the private equity funds in which they invest, signaling a change from the historical trend in which funds could push for aggressive compensation based on the returns they provide. In a poll conducted by Preqin, 43% of investors noted a power shift from fund to limited partner, with only 2% seeing a shift toward the general partner.

In this week's Barron's [a paid service], there's an in-depth look at the mega IPO of the Blackstone Group (NYSE: BX). It's the most important IPO since the offering of Google (NASDAQ: GOOG), although investors shouldn't expect the same kind of returns.

While Google signaled a burst of growth in online advertising (which appears to be long-term), it looks like Blackstone is really signaling a top in the private equity space. Why?

Here are some bullet points:

Competition: KKR, Goldman Sachs (NYSE: GS), TPG, Apollo Management and others all have big war chests and are competing for deals. This drives up valuations -- making it more difficult to get strong returns. This is essentially what happened with venture capital during the internet boom.

Institutional Pushback: Institutions and hedge funds are pushing for higher prices on buyouts. An example is the Clear Channel (NYSE: CCU) deal.

Higher Interest Rates: Private equity has been blessed with dirt-cheap interest rates and this makes it easier to generate returns. But with interest rates climbing, things are getting more difficult.

Politics: Capitol Hill needs more tax revenues. So why not raise rates on private equity?

Yes, Blackstone has posted a stunning 22.6% average annual rate of return (adjusted for fees) since 1987. But, with all these ominous trends, will Blackstone continue the pace? And, is it worth paying 2 times the multiples of companies like Goldman Sachs and Morgan Stanley (NYSE: MS)?

Tom Taulli is the author of various books, including the Complete M&A Handbook and the EDGAR-Online Guide to Decoding Financial Statements.