Gillespie's not in good enough form to keep the runs down currently, and even if his form improves, Lee's wicket taking ability is more important.
Indeed, if Gillespie does hit form, having McGrath, Warne or Gillespie down the other end keeping it tight only makes things easier for Lee. The fact that people are also not realising, is that Lee is bowling far less bad balls now that he used to (as I've been saying for 6 months now), and that you can't simply "wait for his bad ball" because if you do that the way he's bowling at the moment, he bowls maidens. Yes, you can handle a few maidens in tests, but even there if you're not scoring, especially with McGrath down the other end, the pressure builds.
There's also the point that when someone is throwing down 90 mph outswingers, "seeing him off" is not as simple as it sounds.
As far as I can see it, Lee's problem in tests that he has to overcome is what he does when he doesn't get a wicket for a while. The Lee of old basically had two options. He put it right up there and looked for swing, usually away, sometimes coming back in a fraction, or if it wasn't swinging he jammed it in short at the ribs and tried to scare you out. This still worked enough for him to get a wicket every 53 balls, but not well enough to make him a top class fast bowler in tests. His other problem of course was that even when it was working, he really wasn't accurate enough to do it often. He could bowl it quick and get it to swing, but he'd often spray it all over the place in the process.
The second problem Lee has already corrected. His economy rate is going down in ODIs, because he's improved his accuracy so much. Now, when the ball is swinging, he puts 5-6 balls up there, moving around, on or outside off stump. That's fine, and he'll do well in tests like that and I'm confident that alone will see a significant improvement in his test performances.
His other problem we're yet to see his answer to. Lee still goes to pieces a bit when he's getting smashed around, and does suffer from a lack of variation and a quality "stock ball" which he can keep putting up there that the batsman can't hit... which McGrath, Gillespie and Kasprowicz all have. The only way you can really develop this asset is in 4 or 5 day cricket which Lee hasn't been playing for 18 months now. He can still be a good test bowler, certainly good enough to make the team, the way he is bowling now. He's a handy batsman and an excellent fielder to go with it, he adds extra variation to the attack, and he's done well enough in the ODIs so far that England will be wary of him, while Gillespie is just going to get pounded the way things are going. To become a world class test bowler, he's got to work on his options when things aren't going well for him, because he's 28 and there will come a time when he can't just be used in vicious bursts at the top order and come back when it's reversing.
Regarding the third seaming spot, I'm leaning increasingly towards Kasprowicz, as harsh as it is to drop a proven performer like Gillespie at just 30 years of age. He just doesn't look up to the task currently. Maybe pick him at Lords, but if things don't work out there and Kasprowicz does well tomorrow and in the four day warmup match, Gillespie might find himself carrying drinks for a while, and with Tait in the wings who knows when he will get another chance.
